Impact Tough SQ2 Screwdriver Bits Set S2 ALLOY STEEL High high quality material bits set, anti-slip, and anti-corrosion anti-impact and tough, large put on resistant Strong magnetic, good workmanship, excessive precision Absorbs excessive torque of affect driver to avold fracture when heavy screw using 30X lifetime over usual bit Strong Magnetic PRECISION MACHINED TIP Heat-treated manufacturing for stronger bit Precision machined methods with advanced fitment for complete touch fit and longer life