853/4 Harpoon ACR® bits, PH 2 x 152 mmHigh quality bits with reduced shaft diameter for low-lying screw connections. Countersinking of screws without any surface damage. Come with rough ribs (anti cam-out feature, ACR®) to prevent any slipping out of the screw head. Tough viscous for universal use. hexagon, suitable for holders as per DIN ISO 1173-F 6.3