Color-coded bright green to indicate grounding. Specifically designed to make positive ground connections and bond non-metallic sheathed cable. Live action, square wire spring automatically adjusts to wire shape and size while twisting wires together. Hole at top of wing nut for grounding wires from system to ground terminal and box. Pressure-type screw-on connector for use with 1 #10 with 1 or 2 #12, 1 #10 with 1 to 3 #14, 1 or 2 #12 with 1 to 3 #14, 3 #12 with 1 #14, 2 to 4 #12, 2 to 2 #14. Copper-to-copper, green. UL listed.