The Algo 81X8TBR T-Bar & Joist Support Bracket, made of steel, transfers the weight of the Algo 8188 / 8198 / 1198 SIP Ceiling Speaker onto your existing T-Bar rails (cross tee) that hold up ceiling tiles. Alternatively the 81X8TBR is also designed for mounting to wooden ceiling joists/framing timbers. Instead of mounting the Algo 8188 / 8198 / 1198 SIP speaker (not included) directly to the ceiling tile material, the Algo 8188TBR brackets provide additional safety and security and is recommended in earthquake prone areas and to reduce chance of accidents as existing ceiling tiles may age, weaken, and degrade due to moisture or water leak. Please note any image shown is representative and may not be the actual product or color. Please see the manual for proper installation techniques. This product was previously known as the Algo 8188TBR .