Voice Evacuation Speaker/Strobes with Field-Selectable 25 VRMS or 70.7 VRMS Applications -- The SSPK24CLP Low Profile Series of speaker/strobes meets strict codes for audio and visual signaling as well as voice communications. These speakers offer audible signaling, crisp, clear voice clarity and visual signaling. Off-white faceplates can be wall mounted to a standard 2 1/8" deep electrical backbox or standard 4" square box. All models can be synchronized using the Gentex synchronization module.