diff --git a/grc/CMakeLists.txt b/grc/CMakeLists.txt
index 4034c00..b5f317f 100644
--- a/grc/CMakeLists.txt
+++ b/grc/CMakeLists.txt
@@ -11,5 +11,6 @@ install(FILES
     UTAT_HERON_esttc_framer.block.yml
     UTAT_HERON_esttc_deframer.block.yml
     UTAT_HERON_tagged_stream_tail_tagger.block.yml
-    UTAT_HERON_tagged_stream_bufferer.block.yml DESTINATION share/gnuradio/grc/blocks
+    UTAT_HERON_tagged_stream_bufferer.block.yml
+    UTAT_HERON_tagged_stream_fixed_length_padder.block.yml DESTINATION share/gnuradio/grc/blocks
 )
diff --git a/grc/UTAT_HERON_tagged_stream_fixed_length_padder.block.yml b/grc/UTAT_HERON_tagged_stream_fixed_length_padder.block.yml
new file mode 100644
index 0000000..4b4ca96
--- /dev/null
+++ b/grc/UTAT_HERON_tagged_stream_fixed_length_padder.block.yml
@@ -0,0 +1,50 @@
+id: UTAT_HERON_tagged_stream_fixed_length_padder
+label: Tagged Stream Fixed Length Padder
+category: '[UTAT]'
+
+templates:
+  imports: from gnuradio import UTAT_HERON
+  make: UTAT_HERON.tagged_stream_fixed_length_padder(${len_tag_key}, ${final_samples_per_symbol}, ${final_buffer_len})
+
+#  Make one 'parameters' list entry for every parameter you want settable from the GUI.
+#     Keys include:
+#     * id (makes the value accessible as keyname, e.g. in the make entry)
+#     * label (label shown in the GUI)
+#     * dtype (e.g. int, float, complex, byte, short, xxx_vector, ...)
+#     * default
+parameters:
+- id: len_tag_key
+  label: Length Tag Name
+  dtype: string
+  default: packet_len
+- id: final_samples_per_symbol
+  label: Final Samples per Symbol
+  dtype: float
+- id: final_buffer_len
+  label: Final buffer Length
+  dtype: int
+# - id: threshold
+#   label: Threshold
+#   dtype: float
+#   default: 1
+
+#  Make one 'inputs' list entry per input and one 'outputs' list entry per output.
+#  Keys include:
+#      * label (an identifier for the GUI)
+#      * domain (optional - stream or message. Default is stream)
+#      * dtype (e.g. int, float, complex, byte, short, xxx_vector, ...)
+#      * vlen (optional - data stream vector length. Default is 1)
+#      * optional (optional - set to 1 for optional inputs. Default is 0)
+inputs:
+- label: in
+  domain: stream
+  dtype: byte
+
+outputs:
+- label: out
+  domain: stream
+  dtype: byte
+
+#  'file_format' specifies the version of the GRC yml format used in the file
+#  and should usually not be changed.
+file_format: 1
diff --git a/include/gnuradio/UTAT_HERON/CMakeLists.txt b/include/gnuradio/UTAT_HERON/CMakeLists.txt
index 1e9db4a..31c3d4a 100644
--- a/include/gnuradio/UTAT_HERON/CMakeLists.txt
+++ b/include/gnuradio/UTAT_HERON/CMakeLists.txt
@@ -16,5 +16,6 @@ install(FILES
     esttc_framer.h
     esttc_deframer.h
     tagged_stream_tail_tagger.h
-    tagged_stream_bufferer.h DESTINATION include/gnuradio/UTAT_HERON
+    tagged_stream_bufferer.h
+    tagged_stream_fixed_length_padder.h DESTINATION include/gnuradio/UTAT_HERON
 )
diff --git a/include/gnuradio/UTAT_HERON/tagged_stream_fixed_length_padder.h b/include/gnuradio/UTAT_HERON/tagged_stream_fixed_length_padder.h
new file mode 100644
index 0000000..a77a493
--- /dev/null
+++ b/include/gnuradio/UTAT_HERON/tagged_stream_fixed_length_padder.h
@@ -0,0 +1,48 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2023 University of Toronto Aerospace Team.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#ifndef INCLUDED_UTAT_HERON_TAGGED_STREAM_FIXED_LENGTH_PADDER_H
+#define INCLUDED_UTAT_HERON_TAGGED_STREAM_FIXED_LENGTH_PADDER_H
+
+#include <gnuradio/UTAT_HERON/api.h>
+#include <gnuradio/tagged_stream_block.h>
+
+namespace gr {
+namespace UTAT_HERON {
+
+/*!
+ * \brief <+description of block+>
+ * \ingroup UTAT_HERON
+ *
+ */
+class UTAT_HERON_API tagged_stream_fixed_length_padder
+    : virtual public gr::tagged_stream_block
+{
+public:
+    typedef std::shared_ptr<tagged_stream_fixed_length_padder> sptr;
+
+    /*!
+     * \brief Return a shared_ptr to a new instance of
+     * UTAT_HERON::tagged_stream_fixed_length_padder.
+     *
+     * To avoid accidental use of raw pointers,
+     * UTAT_HERON::tagged_stream_fixed_length_padder's constructor is in a private
+     * implementation class. UTAT_HERON::tagged_stream_fixed_length_padder::make is the
+     * public interface for creating new instances.
+     */
+    static sptr make(
+        const std::string& len_tag_key,
+        float final_samples_per_symbol,
+        int final_buffer_len
+        // float threshold
+    );
+};
+
+} // namespace UTAT_HERON
+} // namespace gr
+
+#endif /* INCLUDED_UTAT_HERON_TAGGED_STREAM_FIXED_LENGTH_PADDER_H */
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index b7f9231..e15edb8 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -26,7 +26,8 @@ list(APPEND UTAT_HERON_sources
     esttc_framer_impl.cc
     esttc_deframer_impl.cc
     tagged_stream_tail_tagger_impl.cc
-    tagged_stream_bufferer_impl.cc )
+    tagged_stream_bufferer_impl.cc
+    tagged_stream_fixed_length_padder_impl.cc )
 
 set(DEBUG_FILE "${CMAKE_BINARY_DIR}/debug_log.txt" CACHE FILEPATH
 "Log debug to this file when CMAKE_BULD_TYPE is Debug or RelWithDebInfo")
diff --git a/lib/tagged_stream_fixed_length_padder_impl.cc b/lib/tagged_stream_fixed_length_padder_impl.cc
new file mode 100644
index 0000000..51b636d
--- /dev/null
+++ b/lib/tagged_stream_fixed_length_padder_impl.cc
@@ -0,0 +1,97 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2023 University of Toronto Aerospace Team.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "tagged_stream_fixed_length_padder_impl.h"
+#include <gnuradio/io_signature.h>
+
+namespace gr {
+namespace UTAT_HERON {
+
+using input_type = uint8_t;
+using output_type = uint8_t;
+
+tagged_stream_fixed_length_padder::sptr tagged_stream_fixed_length_padder::make(
+    const std::string& len_tag_key,
+    float final_samples_per_symbol,
+    int final_buffer_len
+    // float threshold
+)
+{
+    return gnuradio::make_block_sptr<tagged_stream_fixed_length_padder_impl>(
+        len_tag_key,
+        final_samples_per_symbol,
+        final_buffer_len
+        // threshold
+    );
+}
+
+
+/*
+ * The private constructor
+ */
+tagged_stream_fixed_length_padder_impl::tagged_stream_fixed_length_padder_impl(
+    const std::string& len_tag_key,
+    float final_samples_per_symbol,
+    int final_buffer_len
+    // float threshold
+) :
+    gr::tagged_stream_block(
+        "tagged_stream_fixed_length_padder",
+        gr::io_signature::make(1,1,sizeof(input_type)),
+        gr::io_signature::make(1,1,sizeof(output_type)),
+        len_tag_key),
+    d_sps(final_samples_per_symbol),
+    d_buffer_len(final_buffer_len),
+    // d_threshold(threshold),
+    // d_min_samps(std::ceil(d_buffer_len + d_threshold)),
+    d_samps_out(0)
+{}
+
+/*
+ * Our virtual destructor.
+ */
+tagged_stream_fixed_length_padder_impl::~tagged_stream_fixed_length_padder_impl() {}
+
+int tagged_stream_fixed_length_padder_impl::calculate_output_stream_length(
+    const gr_vector_int& ninput_items)
+{
+    // int len = static_cast<int>(std::ceil((d_min_samps - d_samps_out)/d_sps));
+    int len = d_buffer_len + 1*d_sps;
+    if(len/d_sps < ninput_items[0])
+        throw std::runtime_error("Input needs to be smaller!");
+    return len;
+}
+
+int tagged_stream_fixed_length_padder_impl::work(int noutput_items,
+                                                 gr_vector_int& ninput_items,
+                                                 gr_vector_const_void_star& input_items,
+                                                 gr_vector_void_star& output_items)
+{
+    auto in = static_cast<const input_type*>(input_items[0]);
+    auto out = static_cast<output_type*>(output_items[0]);
+
+    int produced = 0;
+
+    std::memcpy(out, in, ninput_items[0]*sizeof(input_type));
+    d_samps_out += ninput_items[0]*d_sps;
+    produced = ninput_items[0];
+
+    while(d_samps_out < d_buffer_len && produced < noutput_items){
+        out[produced++] = 0xCC;
+        d_samps_out += d_sps;
+    }
+
+    if(d_samps_out < d_buffer_len)
+        throw std::runtime_error("Output needs to be larger!");
+    
+    d_samps_out -= produced*d_sps;
+    return produced;
+
+}
+
+} /* namespace UTAT_HERON */
+} /* namespace gr */
diff --git a/lib/tagged_stream_fixed_length_padder_impl.h b/lib/tagged_stream_fixed_length_padder_impl.h
new file mode 100644
index 0000000..6a25f12
--- /dev/null
+++ b/lib/tagged_stream_fixed_length_padder_impl.h
@@ -0,0 +1,48 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2023 University of Toronto Aerospace Team.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#ifndef INCLUDED_UTAT_HERON_TAGGED_STREAM_FIXED_LENGTH_PADDER_IMPL_H
+#define INCLUDED_UTAT_HERON_TAGGED_STREAM_FIXED_LENGTH_PADDER_IMPL_H
+
+#include <gnuradio/UTAT_HERON/tagged_stream_fixed_length_padder.h>
+
+namespace gr {
+namespace UTAT_HERON {
+
+class tagged_stream_fixed_length_padder_impl : public tagged_stream_fixed_length_padder
+{
+private:
+    // Nothing to declare in this block.
+    float d_sps;
+    int d_buffer_len;
+    // float d_threshold;
+    // int d_min_samps;
+    float d_samps_out;
+
+protected:
+    int calculate_output_stream_length(const gr_vector_int& ninput_items);
+
+public:
+    tagged_stream_fixed_length_padder_impl(
+        const std::string& len_tag_key,
+        float final_samples_per_symbol,
+        int final_buffer_len
+        // float threshold
+    );
+    ~tagged_stream_fixed_length_padder_impl();
+
+    // Where all the action really happens
+    int work(int noutput_items,
+             gr_vector_int& ninput_items,
+             gr_vector_const_void_star& input_items,
+             gr_vector_void_star& output_items);
+};
+
+} // namespace UTAT_HERON
+} // namespace gr
+
+#endif /* INCLUDED_UTAT_HERON_TAGGED_STREAM_FIXED_LENGTH_PADDER_IMPL_H */
diff --git a/python/UTAT_HERON/CMakeLists.txt b/python/UTAT_HERON/CMakeLists.txt
index c071ebe..d11f13a 100644
--- a/python/UTAT_HERON/CMakeLists.txt
+++ b/python/UTAT_HERON/CMakeLists.txt
@@ -44,3 +44,4 @@ GR_ADD_TEST(qa_esttc_framer ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_
 GR_ADD_TEST(qa_esttc_deframer ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_esttc_deframer.py)
 GR_ADD_TEST(qa_tagged_stream_tail_tagger ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_tagged_stream_tail_tagger.py)
 GR_ADD_TEST(qa_tagged_stream_bufferer ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_tagged_stream_bufferer.py)
+GR_ADD_TEST(qa_tagged_stream_fixed_length_padder ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_tagged_stream_fixed_length_padder.py)
diff --git a/python/UTAT_HERON/bindings/CMakeLists.txt b/python/UTAT_HERON/bindings/CMakeLists.txt
index e01071d..7f1a34b 100644
--- a/python/UTAT_HERON/bindings/CMakeLists.txt
+++ b/python/UTAT_HERON/bindings/CMakeLists.txt
@@ -33,7 +33,8 @@ list(APPEND UTAT_HERON_python_files
     esttc_framer_python.cc
     esttc_deframer_python.cc
     tagged_stream_tail_tagger_python.cc
-    tagged_stream_bufferer_python.cc python_bindings.cc)
+    tagged_stream_bufferer_python.cc
+    tagged_stream_fixed_length_padder_python.cc python_bindings.cc)
 
 GR_PYBIND_MAKE_OOT(UTAT_HERON
    ../../..
diff --git a/python/UTAT_HERON/bindings/docstrings/tagged_stream_fixed_length_padder_pydoc_template.h b/python/UTAT_HERON/bindings/docstrings/tagged_stream_fixed_length_padder_pydoc_template.h
new file mode 100644
index 0000000..9dd18fd
--- /dev/null
+++ b/python/UTAT_HERON/bindings/docstrings/tagged_stream_fixed_length_padder_pydoc_template.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright 2023 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Radio
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ */
+#include "pydoc_macros.h"
+#define D(...) DOC(gr, UTAT_HERON, __VA_ARGS__)
+/*
+  This file contains placeholders for docstrings for the Python bindings.
+  Do not edit! These were automatically extracted during the binding process
+  and will be overwritten during the build process
+ */
+
+
+static const char* __doc_gr_UTAT_HERON_tagged_stream_fixed_length_padder = R"doc()doc";
+
+
+static const char* __doc_gr_UTAT_HERON_tagged_stream_fixed_length_padder_make =
+    R"doc()doc";
diff --git a/python/UTAT_HERON/bindings/python_bindings.cc b/python/UTAT_HERON/bindings/python_bindings.cc
index 5a98154..42c9654 100644
--- a/python/UTAT_HERON/bindings/python_bindings.cc
+++ b/python/UTAT_HERON/bindings/python_bindings.cc
@@ -27,6 +27,7 @@ namespace py = pybind11;
     void bind_esttc_deframer(py::module& m);
     void bind_tagged_stream_tail_tagger(py::module& m);
     void bind_tagged_stream_bufferer(py::module& m);
+    void bind_tagged_stream_fixed_length_padder(py::module& m);
 // ) END BINDING_FUNCTION_PROTOTYPES
 
 
@@ -62,5 +63,6 @@ PYBIND11_MODULE(UTAT_HERON_python, m)
     bind_esttc_deframer(m);
     bind_tagged_stream_tail_tagger(m);
     bind_tagged_stream_bufferer(m);
+    bind_tagged_stream_fixed_length_padder(m);
     // ) END BINDING_FUNCTION_CALLS
 }
\ No newline at end of file
diff --git a/python/UTAT_HERON/bindings/tagged_stream_fixed_length_padder_python.cc b/python/UTAT_HERON/bindings/tagged_stream_fixed_length_padder_python.cc
new file mode 100644
index 0000000..d10d56e
--- /dev/null
+++ b/python/UTAT_HERON/bindings/tagged_stream_fixed_length_padder_python.cc
@@ -0,0 +1,51 @@
+/*
+ * Copyright 2023 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Radio
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ */
+
+/***********************************************************************************/
+/* This file is automatically generated using bindtool and can be manually edited  */
+/* The following lines can be configured to regenerate this file during cmake      */
+/* If manual edits are made, the following tags should be modified accordingly.    */
+/* BINDTOOL_GEN_AUTOMATIC(0)                                                       */
+/* BINDTOOL_USE_PYGCCXML(0)                                                        */
+/* BINDTOOL_HEADER_FILE(tagged_stream_fixed_length_padder.h) */
+/* BINDTOOL_HEADER_FILE_HASH(e8323f50cc6fbf2d718fb4d63b0947d6)                     */
+/***********************************************************************************/
+
+#include <pybind11/complex.h>
+#include <pybind11/pybind11.h>
+#include <pybind11/stl.h>
+
+namespace py = pybind11;
+
+#include <gnuradio/UTAT_HERON/tagged_stream_fixed_length_padder.h>
+// pydoc.h is automatically generated in the build directory
+#include <tagged_stream_fixed_length_padder_pydoc.h>
+
+void bind_tagged_stream_fixed_length_padder(py::module& m)
+{
+
+    using tagged_stream_fixed_length_padder =
+        gr::UTAT_HERON::tagged_stream_fixed_length_padder;
+
+
+    py::class_<tagged_stream_fixed_length_padder,
+               gr::block,
+               gr::basic_block,
+               std::shared_ptr<tagged_stream_fixed_length_padder>>(
+        m, "tagged_stream_fixed_length_padder", D(tagged_stream_fixed_length_padder))
+
+        .def(py::init(&tagged_stream_fixed_length_padder::make),
+             py::arg("len_tag_key"),
+             py::arg("final_samples_per_symbol"),
+             py::arg("final_buffer_len//floatthreshold"),
+             D(tagged_stream_fixed_length_padder, make))
+
+
+        ;
+}
diff --git a/python/UTAT_HERON/qa_tagged_stream_fixed_length_padder.py b/python/UTAT_HERON/qa_tagged_stream_fixed_length_padder.py
new file mode 100755
index 0000000..cdd2a45
--- /dev/null
+++ b/python/UTAT_HERON/qa_tagged_stream_fixed_length_padder.py
@@ -0,0 +1,39 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2023 University of Toronto Aerospace Team.
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+
+from gnuradio import gr, gr_unittest
+# from gnuradio import blocks
+try:
+    from gnuradio.UTAT_HERON import tagged_stream_fixed_length_padder
+except ImportError:
+    import os
+    import sys
+    dirname, filename = os.path.split(os.path.abspath(__file__))
+    sys.path.append(os.path.join(dirname, "bindings"))
+    from gnuradio.UTAT_HERON import tagged_stream_fixed_length_padder
+
+class qa_tagged_stream_fixed_length_padder(gr_unittest.TestCase):
+
+    def setUp(self):
+        self.tb = gr.top_block()
+
+    def tearDown(self):
+        self.tb = None
+
+    def test_instance(self):
+        # FIXME: Test will fail until you pass sensible arguments to the constructor
+        instance = tagged_stream_fixed_length_padder('packet_len')
+
+    def test_001_descriptive_test_name(self):
+        # set up fg
+        self.tb.run()
+        # check data
+
+
+if __name__ == '__main__':
+    gr_unittest.run(qa_tagged_stream_fixed_length_padder)