Our Guard is designed to extend the life of the wooden 2×4 by protecting it from low shots and bullet fragments. The Guard is constructed from 3/8″ AR500 Brinell Steel. Guard comes pre-drilled to accept the (2) 1/2″ carriage bolts and nuts. The Guard can also be used to splice two short sections of wooden 2×4 pieces together making one longer section. (bolts and nuts not included).