Sealey 16 piece impact socket set deep 1 2in square drive metric imperial sealey ak685 p this 16 piece deep impact socket set from sealey uses the duometric reg selection principle where no imperial size socket is included where there is a metric equivalent this method gives maximum coverage of sizes with the minimum number of sockets p p all sockets are walldrive reg and allow transfer of up to 30 more torque to the fixing before the risk of damage to the corners of the hexagon this