The GMP Tools Duct Clamp, 1 in (part 89961, Millennium part 527108), secures a GMP cable blower onto 1-inch duct, keeping the machine locked in place against air pressure while cable is jetted through the run. Crews swap clamp sizes between jobs so one blower can handle multiple duct diameters without buying a dedicated machine for each. A properly seated clamp prevents air loss that would otherwise cut blow distance short. Order it with matching duct seals and clamp-and-seal kits for the rest of the duct size range.