Louroe Audio Monitoring TLSP-PB-F 3 inch speaker and electret condenser microphone mounted on the back of a 11 gauge stainless steel face plate. Contains a call button that can activate the alarming base station (ALA/DG Series) in addition to sound activation. A special built-in sound path protects both speaker (2W Power Rating) and microphone from abuse. Unit designed for correctional facilities. Security hardware included. These units compatible only with Louroe sound activated base stations (Model DG-12II/DG-25III and the ALA-4/8 series). IMPORTANT: For flush mounting, request TLSP-PB-F. For surface mounting, request TLSP-PB-S. Dimensions: TLSP-PB-F face plate: 7 inch W x 7 inch H. TLSP-PB-S face plate: 6 1/4 inch W x 6 1/4 inch H. Back box (included): 6 inch W x 6 inch H x 4 inch D