These 6.00" long jaws are 1.25" thick by 2.00" tall.  They are made from 6061 aluminum. Bolt spacing is 3.88".  The bolt detail is for a 1/2-13 socket head cap screw.  Adequate clearance allows for ease installing & removing the bolts.  The bolt detail has a .35" remainder.  This sets the head of the screw recessed in the jaw; allowing for tapped holes and drills to enter below the work piece even after milled down from use. These jaws are also completely deburred.  No sharp edges, heavy break-edge all around. 

Listing is for 2 jaws 1 set

I use washers that are a special size. They fit into the counterbore. They are the same diameter as the socket head Allen bolt. The reason why these washers are a must, is to allow the jaws to be tapped down flat. Without washers, from reuse the bolts digs into the aluminum and lifts the jaw. So, remove and remount your jaws with zero fight to tap them flat. Also, great for saved jaws with special shapes milled onto the jaws. These washers are called:

Low carbon steel round shim .06 thick 1/2 ID 
The OD will show 3/4 OD
McMaster Carr