... : [For example 4ch wireless switch]Press remoter button A first time,the receiver relay is ON,press remoter button A secondtime,the receiver relay ... B/C/D. Extend function:When Jumper is OFFpossition, when press button A on the transmitter, receiver channel A goes on 2 ... 3):Commutative lock model:[For example 4ch wireless switch] Press remote button A,the receiver relay A is ON,the relay B ...