These mounting clamps by S&P connect and disconnect round ventilation duct. The vent mounting clamps have an insulated rubber duct seal that will secure ducting together to insure a leak-free fitting. The vent mounting clamps are made from galvanized steel and are fully adjustable with two screws. These connector clamps are available for 4",5",6",8",10" and 12-2/5" ducting. The clamps ship via UPS.