Aerocel EPDM Tube Isolator is a flexible, cell-shaped Isolator and of lightweight elastomeric material Designed for cooling insulation and enclosed liquid line heating. Aerocel EPDM Isolator Tube is available in 3/8 ", 1/2", 3/4 ", 1" and 1-1 / 2 ", and popular sizes up to 1-5/8" ID. The closing cell structure of the EPDM Aerocel Tubes Pipe insulator makes the most efficient elastomer insulation. Aerocel EPDM Tube Isolator offers the only truly UV resistant HVAC insulating pipe, this type of heat retaining material does not require additional protection from degradation weathering, as it is formulated by using EPDM rubber.