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 1/4-28 UNF bolts have a 2 1/4" under-head length including the 1 1/4" long grip (unthreaded portion).  The 12-point head takes a small 5/16" wrench, but has a full-size 0.515" diameter bearing surface.  Head measures 0.255" high.