supply of 1) 3/4 inch square coupler 2) hand operated knurled grip screwdriver bit socket1) 3/4 inch square coupler 2) hand operated knurled grip screwdriver bit socket,3/4 inch square coupler accoring to din 3122 iso 3315, suitable for torque wrench and ha nd operated sockets with square drive as per iso 1174, with locking pin. length 51.5mm(approx). marerial: chrome vanadium steel,chrome plated. make/brand:gedore/norbar/facom/stahlwhile/heyco. [ warranty period: 30 months after the date of delivery ] ] , hand operated knurled grip screwdriver bit socket according to din7422,with 3/4 inch s quare drive and hexagonal male allen bit of dia 17mm for m20 in-hex screws. square drive as per din 312 0-d20, iso 1174 with locking pin.made of vanadium special steel, manganese phosphate with chrome plati ng. overall lenght 80 mm(approx). make/brand: gedore/norbar/facom/stahlwhile/heyco. [ warranty period: 30 months after the date of delivery ] ]