The Gentex 901-0323 GCSB Ceiling Surface Back Box-White is designed to work with the Gentex Commander series strobes and horn/strobes. The Back Box is constructed of durable plastic and features 1/2" conduit knockouts.
This ceiling surface back box comes with wiremold knockouts for the 500 and 700 series and 1 and 1/2" inch maximum diameter pendant mount. It mounts to the surface of most electrical boxes and is meant for indoor use only. With metal washer reinforcements for the conduit knockouts and hidden screwheads, the Gentex 901-0323 ceiling surface back box is 6.2" round by 1.67".