Protect speaker installations in plenum return-air ceilings with the S-551-5, a five-pack of Valcom steel ceiling speaker backboxes with fire-retardant dampening material already installed for code-compliant plenum deployments. The Telecom Spot Expert Review Plenum-rated backboxes are not optional when your ceiling is part of the HVAC return air path — fire codes require the fire retardant lining that the S-551-5 includes. Buying in packs of five keeps job site inventory tidy and cuts the per-unit cost. The five knockout options give installers flexibility for conduit or cable routing from any direction, so you are not locked into a single entry point at the ceiling box. Key Features Plenum-rated fire retardant dampening material — meets return-air ceiling code requirements 5 knockouts for flexible conduit and cable routing Sturdy steel construction for long-term rigidity above the ceiling Sold in packs of 5 — efficient for multi-room and multi-floor installations Compatible with Valcom ceiling speaker models requiring backbox support Technical Specifications Model S-551-5 Quantity 5 per pack Material Steel Knockouts 5 Plenum Rating Fire Retardant Dampening Material Included Application Plenum Return-Air Ceiling Speaker Installations
