Duda Solar 1" ID 19mm Thick 6 Ft Super Nitrile Rubber Pipe Insulation R2.9 Water Resistant Nitrile/Rubber is water and high temp resistant, Great for solar water heater systems Thickness: 19mm (3/4"), Length: 6 ft, R-Value = 2.9, Thermal Conductivity of Rubber: 0.038 W/m2K Fits 3/4" Nominal Copper & 1" Corrugated Stainless Steel Tubing, Fits 1/2" SCH40 Iron or PVC Pipe ID: 1", OD: 2.50", Max Temp: 100C (212F) Flexible & easy to use, Greatly outperforms standard foam insulation