I was reading into this and it is very similar to the SAFC. and i was wondering if anyone has used this to controll their injectors?

 

i have a HKS AFR in my car. Previus owner had it installed. I dont touch the damn thing. It is an overall setting.

mine is a little older then the ones hks has now. its just a flat little panel with a dial on it for richer/leaner. Doesnt have rpm increments or anything.