Bolt - 3/8-16 in Thread - 1.500 in Long - 3/8 in 12 Point Head - Stainless - Polished - Universal - Set of 5Automotive Racing Products (ARP) started in 1968, in Southern California. Their product line includes everything from engine and driveline fasteners for OEM replacement parts to exotic specialty hardware for the Formula 1, Indycar, NASCAR, NHRA Drag Racing, and Marine Applications. They produce a number of specialty products like cylinder head fastener kits, connecting rod bolts, exhaust manifold/header fastener kits, oil pan fastener kits, piston ring compressors, and more.