The IDEAL Twister Al/Cu is the only UL listed aluminum-to-copper twist-on connector that prevents aluminum oxidation while providing a secure connection. Specially formulated corrosion-resistant compound penetrates corrosion build-up on aluminum conductor Aluminum-to-copper and copper-to-copper twist-on connector ; For a complete list of approved aluminum to copper wiring combinations ; Compact, one-piece design features ribbed cap, swept wings and hexagonal head for easy installation by hand or with standard nut driver ; Live-action, square-wire spring expands and contracts with aluminum wiring ; Deep skirt provides maximum dielectric strength ; Tough UL 94 Volt-2 flame-retardant shell rated at 221°F ; Made in the U.S.A. of U.S. and global components^^Dimensions ; Product Depth: 0.813'' ; Product Width: 0.813'' ; Product Height: 1.344''^^Details ; Color Family: Purple ; Minimum Wire Capacity: 1 #12 Al w/1 #18 Cu ; Electrical Product Type: Wire Connector ; Maximum Wire Capacity: 1 #10 Al solid w/2 #10 Cu solid^^Warranty / Certifications ; Certifications and Listings: UL listed to 486C and CSA certified to C22.2 #188 ; Compliant with federal specification w-s-610E