This Processor Extension Pak is optional for debugging the following devices and is intended for those who wish to debug the PIC16F1509 family of microcontrollers in-circuit, while freeing up I/O pins typically reserved for debugger use: PIC16F1509 and PIC16F1508. The product is required for debugging the following devices: PIC16F1507, PIC16F1503 and PIC12F1501