--- /dev/null
+<?xml version="1.0"?>
+<block>
+ <name>Square</name>
+ <key>howto_square_ff</key>
+ <category>HOWTO</category>
+ <import>from gnuradio import howto</import>
+ <make>howto.square_ff()</make>
+
+ <sink>
+ <name>in</name>
+ <type>float</type>
+ </sink>
+
+ <source>
+ <name>out</name>
+ <type>float</type>
+ </source>
+</block>