Havaco Quick Connect Register Boot with Ceiling Diffuser combinations are even easier to install wont dent or rust and are paintable or with Custom Graphics including wood grain stone camo and other designs. The ceiling boots are 8 6 in. and an 8-7-6 in. reducing model. The diffusers comes in square Capital Crown molding models.Features. Color - White.. Shape - Square.. Capital Crown Ceiling Diffuser.. 8-7-6 in. Boot Rotary Damper.