SuperVent Inner Liner is constructed with 300 Series Stainless Steel with 0.016" thickness and the Outer Casing is constructed with type 430 Stainless Steel with 0.015" thickness. SuperVent 2100 JM chimney is intended for venting gas, liquid, or solid fuel fired residential type appliances and building heating appliances and has twist lock connection for easy assembly. It has been tested and approved to withstand temperatures of up to 2100 degrees F. SuperVent has a 2" space between inner/outer walls that is Solid Packed with Mineral Wool Fibre insulation to provide superior insulation qualities.