The German Style Bone Yard Spike Novelty Helmet Gives You that Great Look. The Bone Yard Spike Novelty Helmet Contains the Following: (A) Metal Quick Release Buckle. (B) "Y" Strap Retention System for a Secure Fit. (C) 4 Ply Fiberglass Shell with Hand Lamination. (D) Fully Lined Liner. (E) Steel Rivets. (F) Your Choice of Either a 4 Inch or 3 Inch Steel Spike. (G) This is a NON D.O.T Certified Helmet.