Channel rail Series SS is engineered to distribute the speaker assembly weight to the ceiling support system in a suspended 2' x 2' or 2' x 4' tile ceiling system. Rails are often required, for safety reasons, by local building codes, and for aesthetics to reduce the potential of unsightly ceiling tile sag. Lowell's channel rail Series SS is galvanized steel with holes to screw mount nearly any recessed ceiling style backbox. Additionally, rails include holes for seismic anchoring where required. Rails are packaged in pairs and include mounting hardware.