This adapter or magnification piece is required when the torque tool has a 1/2 inch (12.5 mm) square and the required nut has a 3/4 inch (20.0 mm) square.
for hand-operated socket wrench inserts
. CV steel
. 12.5 mm(1/2") to 20.0 mm(3/4") Outside square . DIN 3123 / ISO 3316