The Klein Tools Lineman's Insulating 4-in-1 Box Wrench is the only double ended 4-in-1 wrench on the market to meet the ASTM standard 1000V rating. It features a transparent handle that shows the metal ends of the wrench are not touching. The solid, durable wrench features four 12 point socket sizes: 1/2'', 9/16'', 5/8'', and 3/4''.