€¢ Ideal for use with flexible ducts €¢ Feature a quick-release tab for reuse on up to 4 inch ducts €¢ Suitable for use on both 3 inch and 4 inch ducts >> Dundas Jafine's Adjustable/Releasable Plastic Clamps are ideal for use with flexible aluminum foil and vinyl ducts. They also feature a quick-release self-locking clasp."