The 20.4:1 25DX50L MM HP 12V 48 CPR Encoder is a gear motor encoder part manufactured by Pololu. It is a encoder with an integrated 20.4:1 reduction planetary gearbox, a 500 CPR (counts per revolution) quadrature encoder output, and a 12V brushed motor. It offers the user a wide range of gear ratios, and a variety of input output options. The encoder is powered by a 12V supply, and features a 40mm outside diameter, allowing it to fit into tight areas. With a weight of 77g and an included mounting bracket, the encoder can easily be integrated into robotic applications. The encoder also has an integrated 48 cpr encoder, allowing for accurate position and speed detection. The encoder also comes included with both a 3-pin and a 5-pin RJ-45 connector, allowing for quick and easy connection of the encoder.