1. Material: CR-V chrome vanadium steel
2. Size: 21x11x3.5 cm/set
3. Weight: about 640g/set
4. Production process: overall heat treatment, surface plating
5. Specifications: 1/4 inch M4/M5/M6 (6.35 mm), 3/8 inch M8/M9/M10/M12/M14 (10 mm), 1/2 inch M16/M18 (12.6 mm)
6. Standard: metric
7. Features: solid and durable material, complete specifications, wide applicability, built-in non-slip slot at the bottom of the sleeve to prevent falling off, easy to use, surface electroplating, rust-proof and beautiful, high hardness, good toughness