Plastic insulated staples are used to attach Romex , UF, and other type NM cable up to 3-conductor (No. 10). Use the 1/2" for 2-conductor Romex and other type No. 12 and No. 14 NM cable conductors. Use the 3/4" for 3-conductor Romex and other type No. 10 and No. 12 NM cable conductors. Fast and easy-to-install, both of the zinc-plated nails can be driven together without splitting wood. Nail heads recess into the staple for minimum exposure. Made of high-grade UV-resistant polyethylene, they will resist rot, rust, and resist the effects of temperature extremes and the degradation of the ultraviolet rays of sunlight.