The T1100 (steel) diffusers consist of a stamped backpan with an integral round collar and a removable plaque face. The plaque is held in place with four brackets that positively engage into the backpan. The architectural plaque diffusers feature a 4-way horizontal ceiling pattern effective for cooling applications where a clean ceiling appearance is required. The T1100 series diffusers have been carefully engineered for critical aesthetic applications while maintaining excellent performance. The plaque is made of dual thickness metal, which results in a clean appearance due to the absence of spot welds and rivets.