8" Triple-Wall Square Ceiling Support Box

Supports chimney pipe and provides a positive connection between support box and chimney with a built-in twistlock. Suitable for both flat and cathedral (A-Frame) ceiling applications. Also use in short attic spaces (see instructions). Fits between standard 16” on-center joists and most manufactured home applications. Supports up to 60' of DuraTech Chimney. A 2” wide trim collar is included. Painted black. Integrated adapter accepts either single-wall or doublewall stovepipe.