1/4" Proof Chain Mounting Kit with 2 1/2" bolts for mounting to a 2"x4" board We include 2 1/2" bolts for non target end of chain and harder Grade 5 bolts for chain at target end. 2 1/2" bolts for mounting chains to 2"x4" lumber 1/4" proof zinc plated chain Tilts target a little. Keep in mind that we are offering free shipping, also harder target bolts and 2 1/2" bolts for mounting other end of chain.