product code B12B819741 refers to the Roller Assembly Kit for the compact desktop document scanners:
Epson WorkForce DS-C330
Epson WorkForce DS-C490.
The kit includes the primary feed components: the Pickup Roller and the Separation Roller.
These rollers ensure documents are smoothly grabbed from the ADF stack and, most importantly, are fed one sheet at a time (the Separation Roller prevents double-feeds).