Supports chimney pipe and provides a positive connection between support box and chimney with built-in twist-lock. Suitable for both flat and cathedral (A Frame) applications. Also use in short attic spaces. Fits between 16" on-center joists and most manufactured home applications. Supports up to 60' of DuraTech Chimney. Use adapter 8674 to attach DVL or DuraBlack to the support box. A 2" wide trim collar is included, Painted Black