Fiberglass Backing Tape, Overall Width 2 1/2 in, Overall Length 41 ft, Maximum Current 600 A, Compatible Material Type Carbon, Duplex and Chrome Steel, Metal, Stainless Steel, Features Halogen and Chlorofluorocarbon Free Acrylic Base Adhesive, Increases Weld Productivity, Significantly Reduces Setup Time and Weld Clean Up, Form Roll, Material Aluminum, Fiberglass, Process MIG Welding, SMAW, TIG Welding, Product Type Welding Backing Tape, Resistance Properties Heat Resistant Fiback is a heat resistant aluminum tape with a woven fiberglass center strip, designed to eliminate or reduce the need for back purging and post weld grinding. Up to 600 Amps.