What type of encoder is used on the AZ series step-servo hybrid motors?

AZ Series Encoder Information

The AZ Series uses a multi-turn, absolute mechanical encoder that allows for accurate battery less and sensor less feedback from the stepper motor. It can track the motor position in the range of 1800 revolutions (±900 rev bidirectional operation) [900 rev (±450 rev) for NEMA8 and NEMA11 sizes]

ABZO sensor