The Alpha Communications® RCB2400S Refuge Call Boxes are used with the AlphaRefuge™ 2400 Series Area of Refuge system, and are Surface Mount type. The PWRAPC or PWRAPC112 (depending on system capacity) power supply unit can provide power and battery back-up for the RCB2400S Refuge Call Boxes. The RCB2400S Refuge Call Boxes come standard with a built-in heavy-duty metal call button,and are available with an optional mushroom head call button (add Suffix- M).