Hollow-Point Gear Silver Bullet Valve Caps - Metal Bullet Valve Caps for Cars, Trucks, and ATVs. Real Bullet Casings! Nickel Plated Brass Bullet Casing - Authentic Once-Fired Bullet Shell Set of 4 Replacement Valve Caps for Cars, Trucks, Bike, Motorcycles, and ATVs Protect your valve stems from rust, corrosion, rocks, and dirt. Bullet casings provide maximum ballistic durability and protect your valve stems. A portion of profits benefits the Navy SEAL Foundation