Q. I have the 23872 shift selectable Supreme receiver. What is the jumper for?
A. The position of the jumper selects the shift configuration. If you look at the top of the receiver you will see three pins in the configuration slot. If the jumper is grounding the left and middle pins, the receiver will work with negative shift transmitters. If it is grounding the middle and right pins, it will work with positive shift transmitters. The receiver will not work without the jumper.