Finding a SPTS but not a DPDT inductive switch?Not at all. That unit uses a serial decoder to decipher when the reverse signal is triggered in the transmission then signals a reed relay (internally moving parts) to give you an output. I used a small simple inductive proximity switch mounted in the console to indicate the shifting handle is in the reverse position and it fires a solid state relay directly..It is a DPDT unit so one side triggers my back up camera and the other side provides for my reverse light. Total cost about $18. and 1 hour.