V-throat open end head allows four sided grip on the fastener to prevent slippage. High polished nickel chrome plating on Full Polish wrenches resists rust and enhances the appearance of the tool. TDS Torque Dispersing System opening design spreads stress evenly and reduces fastener rounding. 12 Point Full Polish - Nominal Size 13MM - Overall Length 4-3/8" - Head Thickness = Box End 11/32" - Open End 17/64" - Head Diameter = Box End 3/4" - Open End 1-5/64"