For Metal Roofing Panels, Duco 9" Classic Rib Profile Foam Closure Strips - 3' DURABLE ? Duco closure panel strips can resist an incredible range of temperature extremes and block vapor transmission action. Does not fracture, shrink, bleed, dry out or dissolve when exposed to extreme weather and UV conditions. Does not absorb moisture and is highly resistant to most chemicals. VERSATILE ? These flexible and lightweight closures experience uniformed compression and are designed to improve the integrity of your outdoor metal, aluminum, tin, or plastic roof in your particular building or construction environment. ABSORBS SOUND - Duco roof strips reduce noise migration and plug each gap or hole where your corrugated metal roofing panel or ribbed roofing panel meets the support wall, providing a virtual acoustic barrier from the noise outdoors to mask unwanted sound. FITTED ? Duco rigid foam closures insert perfectly into their respective metal panels or other materials of the same profile and offer an interlocking dovetail design. Their weather-tight insulation helps seal out wind, birds, pests, or any rodent and provides water proof support on any buildings such as a greenhouse, barn, home, shed, cabin, house, warehouse, etc. PACKING SIZING - Each pack comes with 20 outside closing strips that are 3 feet in length and have a ridge every 9 inches on center.