Southwark ATDRP6 - 6" Air-Tite Round Pipe Takeoff With DamperModel ATDRP: Air-Tite Round Pipe Takeoff With Damper Material: Hot Dipped Galvanized Steel per ASTM A653 CS Type B, 26 Gauge Collar diameters from 3" to 20" 1/2" overlap with 1/8" rivets RL-2 rivet seam (+/- 4" w.g.) 1 1/4" crimp length 6 1/2" to 14 3/4" tube length Gasket 1 1/2" wide and 1/8" thick; made with high tack adhesive-coated neoprene foam Four 1/8" holes in gasket for sheet metal screw attachment Features a two quad damper (26 gauge with 18 gauge handle secured with wingnut) Standoff fittings available as additions