Crowtail Encoder CT0004EN Elecrow bazaar, Make your making Crowtail easy.

This rotary encoder module encodes the rotation of the axis and outputs the signal by electronic pulse. There are two output pins of this module including signal A and signal B.Users can get the axis rotation angle and the direction, clockwise or counterclockwise, by sensing the output pins, with 20 pulses per circle.
As an incremental rotary encoder, unlike rotary potentiometer, this rotation counts are not limited, and the outputs are digital.