Lambro 284L Worm Gear Clamp, 4 in Duct, Clamping Range: 3-9/16 to 4-1/2 in, Steel, Zinc-Plated

The Lambro 4 in galvanized steel worm gear clamp is ideal for attaching semi-rigid and rigid ducts to vents, exhaust outlets, connectors, elbows and other various connections. These clamps easily adjust using a hex or flat head screwdriver to secure the connection point. It is recommended to use a manual screwdriver to avoid over tightening and stripping the screw.