Toolcraft 820775 1/2" Drive Socket 21mm

Toolcraft 12.5mm (1/2in.) Sockets - Toolcraft 820775, The power transmission from the nuts to the screw head is not via the corners, but via the flanks. This ensures higher power transmission, plus the sensitive edges of the nut remain intact. Toolcraft 820775 1/2" Drive Socket 21mm

Price: 2.86 from Rapid Online Rapid Electronics Ltd.