Brand: Automotive Racing Products (ARP)
These high-strength ARP bolts are great for installing most accessories.  The 180,000 psi tensile strength bolts are made of 8740 chrome moly with a black oxide finish.  Pack of 5 bolts includes matching washers.  
These bolts have 7/16-14 UNC coarse threads and a 2 1/2" under-head length, including the 1 1/4" long grip (unthreaded portion).  The hex head takes a small 7/16" wrench, but has an 0.67" diameter bearing surface*.  Head measures 0.40" high. 
* Standard AN960-716 flat washers have a 0.75" OD.