Plastic clip-on wire markers from Stranco Inc. are an easy and convenient way to mark wires and cables without disconnecting them from terminals. Clip-on markers are also known as snap-on markers or plastic wire markers. Stranco’s high performance clip-on plastic wire markers apply quickly with color coded applicator wands. Simply place the flared end of the wand over the wire, then with your thumb or finger, push the clip-on markers over the wire.