Dual rated aluminum split bolt made from heat-treated aluminum alloy for maximum conductivity and strength for copper and aluminum conductors. Triangular edges bite into the conductor to break through surface oxides which eliminates wire brushing. Electro-tin plating provides low contact resistance. Spacer bar separates dissimilar metals prevents galvanic corrosion. Hex head provides ease of installation with standard wrenches. UL (Underwriter s Laboratories) listed CSA (Canadian Standards Association) certified. 1 per clamshell. WARNING: This product can expose you to chemicals including DEHP which is known to the state of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov - Lead