7Pcs 0.7-3mm Mini Micro Hex Allen L-Key Set Wrench Screwdriver Tool Kit Dedicated to the wrenching socket head cap screws. Precisely-sized, chamfered ends insert smoothly into fastener head, reducing wear. Long arm wrenches provide extra reach and greater torque. Blackening the surface treatment, with high strength, high toughness, wear resistance. Good oxidation resistance.