Drafty penetrations around pipes and ducts that weren't sealed properly show up on the heating bill — and on the inspection when the home energy rater runs the blower door test. Rope caulk is the fastest way to stuff the gap around pipe and duct penetrations in exterior walls without the mess of spray foam in occupied homes. 3/16-inch diameter by 30-foot length covers the most common residential pipe and duct penetrations in exterior walls — the rolls pack flat for truck glove boxes and tool bags. Non-hardening formula stays flexible so it moves with the building without cracking. Works in temperature swings from Midwest summers to Nebraska winters without shrinking or hardening. Standard in the weatherization toolkit of insulation contractors and HVAC crews across northeast Ne Stocked at Crofton Lumber and Akron Lumber.