Brand: Automotive Racing Products (ARP)
These high-strength ARP bolts are great for installing most accessories.  The 170,000 psi tensile strength bolts are made of stainless steel with a polished, corrosion-resistant finish.  Pack of 5 bolts includes matching washers.  
These bolts have a 5/16-18 UNC thread pitch and 9/16" under-head length, with a fully-threaded shank.  The 12-point head takes a small 3/8" wrench, but has a full-size 5/8" diameter bearing surface.  Head measures 0.30" high.