These decorative all metal nickel plated SPIKE bolt caps fit all Harley single and duel handle bar clamps with 5/16 socket head bolts. The spikes are 3/4 inch in diameter at the base, and extend 1 inch beyond the top of the bolt head for a very impressive and unique look. (1.2 inches total length). These spikes are secured to the bolt heads using a drop of silicone adhesive. They also match our other spike bolt caps.