Fanuc A20B-9000-0300 AC spindle sensor. This B type spindle motor sensor is a optical pick up 12 pin feedback device sold with or without cable. Normally for speed, position for the CNC controlling early generation AC spindle motors. This number is the common reference number this sensor is known by, however its order code is A290-1003-V320. Regardless you’ll always get the complete sensor with pcb for your Fanuc spindle motor.
DNC only have stock for AC spindle motor refurbs with these sensors. Testing, fault diagnosis of the A20B90000300 sensor is possible; if sent with the complete motor.