Premium quality #45 steel material, special heat treatment, high hardness, durable toughness. Precision spanner wrench, great for professionals and hobbyists demanding ease of operation and high quality work results. A great auxiliary tool for turning nut , widely used for vehicle repair, machinery repair, etc. Hardness, wearproof, and durable, perfect for equipment installation, debugging, maintain and overhaul working. Easy to operate, 7 types for you choose, practical and convenient for use. Specification: Material: Steel Head Shape: Square Size: Capacity: 22-26mm Thickness: 4mm, Height: 3mm, Length: 126mm. Capacity: 28-32mm Thickness: 4.5mm, Height: 3mm, Length: 142mm. Capacity: 34-36mm Thickness: 5mm, Height: 3.5mm, Length: 153mm. Capacity: 38-42mm Thickness: 6mm, Height: 4mm, Length: 168mm. Capacity: 45-52mm Thickness: 6mm, Height: 4.5mm, Length: 188mm. Capacity: 55-62mm Thickness: 6mm, Height: 5mm, Length: 215mm. Capacity: 68-72mm Thickness: 6mm, Height: 5mm, Length: 235mm. Color: Black Package Includes: 1 Piece Hook Wrench Note: Please allow 1-3mm error due to manual measurement, pls make sure you do not mind before you bid Due to the difference between different monitors, the picture may not reflect the actual color of the item, pls understand, thank you