Description Two-wire staples fasten 2 and 3 conductor non-metallic cable. SIZE: 1/2" x 1" - For 2 conductor (No. 12 and No. 14) NM cable. SIZE: 9/16" x 1-1/4" - For 3 conductor (No. 10 and No. 12) NM, BX, UF and other cable.