google for physical 3way diagram. The idea is pretty much straight forward, in 3-way physical switch, there is a bridge (traveler) wire. This wire's designed to run through every switches (3 switches) in the circuit. to make C4 switches to work with 3-way physical switches. YOU NEED 2X C4 2-button keypads, and 1x C4 switch. 1st box: you wire the C4 switch as color code, green, white, red, black, (cab the traveler wire seperate) 2nd box: all you need is black/white/ground for the first C4 2-button keypads. cab those traveler serate) 3rd box: do the same thing to 2nd box. FINALLY, you need to go to COMPOSER PRO bind, the keypads to the switch.