Description: 8 pcs 4 inch long hex head allen drill bit set. Magnetizable hex bits (new bits with a weak magnet). After being magnetized with a magnet, you can easily suck the screws when used. Can be used with electric screwdriver, manual screwdriver, electric drill, general group tools, etc. Made of impact-resistant S2 tool steel, a hard and abrasion-resistant metal alloy, for peak performance and maximum durability. Allows increased torque when tightening. Exquisite workmanship, each edge can be precisely locked screws, no damage to the screw and screwdriver head. Multi size, 1/4 inch hex shank. Use different sizes to screw, will damage the screwdriver and the screw! Using the right screwdriver bar, pay the least effort and easily unscrew the screws! Specification: ►Material: High quality S2 steel ►Head type: Hex head ►Total length: 4 inch / 100mm ►Shaft type: 1/4 inch hex / 6.35 mm ► Size: H2.5 (2.5mm), H3 (3mm), H4 (4mm), H5 (5mm), H6 (6mm), H8 (8mm), H10 (10mm), H12 (12mm) )