Morris 90412 Bolt Connector with Spacer Dual Rated for Copper and aluminum Conductors Bolts Type Number-6 Wire Range Split Bolt Connectors With Spacer Dual Rated For Copper and Aluminum Conductors - Dual Rated Copper and Aluminum Split Bolt Connector AL9CU Dual rated split bolt connector is UL listed for all combinations of Aluminum, Aluminum to Copper, and Copper to Copper stranded wires 90412~90420 Manufactured from Copper alloy, 90422~90426 manufactured from Aluminum alloy Uniform bright electro-tin plating resists corrosion, reduces contact resistance and gives you maximum conductivity Spacer separates dissimilar conductors and provides long contact length that prevents high pressure point contacts between run and tap connectors