High quality chrome vanadium steel forging, hardness up to HRC55, overall heat treatment, high hardness, large torque, good toughness, strong and durable. Multi-functional design, various models, equivalent to buy one = buy eight, all kinds of maintenance, not afraid of no tools. Keychain design, portable around the waist, compact, convenient and practical. The surface of the wrench is electroplated, beautiful and not easy to rust. The handle is blue anodized to prolong the life of the product. Exquisite workmanship, split design, each can be opened separately, and the tightness of the wrench body can be adjusted. Simple appearance/double hump + middle groove design, scientific storage groove, simple and delicate appearance, the thumb can be reasonably placed in the middle groove when in use, easy to operate.