Bar wire holes are suitable for one #14-4 or up to three #14-10 aluminum or copper wire. Multiple wires in a single hole must be of the same size and material. Distance between mounting holes is 1-3/4 in. Consult local code for correct application of ground bar kit for service entrance equipment. Kit contains one ground bar and two #10-32 x 5/8 in self-threading screws. UL listed.