... control systemindividually or design all the 3 functions together.One is self lock model,anotheris no lock model, ... OFFpossition, when press button A on the transmitter, receiver channel A goes on 2 secondsthen goes off automaticaly...Same ... 4ch wireless switch] Press remote button A,the receiver relay A is ON,the relay B/C/D ... /D is OFF; Press remote button D,the receiver relay D is ON,the relay A/B/C ...