- Double ply: 0055 Type 3003 Aluminum.
- Tested and approved to UL 1777 and UL 441.
- For use in a masonry chimney serving gas burning appliances only.

Not recommended for appliances rated over 83% AFUE. Not for use with coal, oil or wood heating systems.
Backed by a 15 year limited warranty.
SIZE SIZE
3" x 25" 6" x 25"
3" x 35" 6" x 35"
4" x 25" 7" x 25"
4" x35" 7" x 35"
5" x 25" 8" x 25"
5" x 35" 8" x 35"