28 gauge G-90 ASTM-A653 CS Galvanized steel Adjustable slip tab provides a snug fit around the vent Locking tab secures installation Complies with ANSI / UL 441 Continuous service temperature range of -65°F (-54°C) to 250°F (121°C); do not use petroleum-base mastics, sealing compounds, or paints on collar portion of all flashings, on all hardbase, flexible or rain collars This storm collar works together with the Water-Tite Type B Vent Flashing to provide a waterproof seal where the stack passes through the roof. The storm collar is installed and sealed directly above the flashing.