This Harmony XB4 flush wireless and batteryless push button and receiver unit set is supplied with a set of 10 colored caps and uses a 24V to 240V AC input.It has a metal bezel.This wireless batteryless push button provides a simple and reliable solution for remote control of machines, conveyors and cranes.The button is easily installed into standard 22mm diameter panel cut-outs, while the receiver is DIN rail mountable.