Made of high quality carbon steel, high hardness and strength, also very durable. Self-Adjusting Wrench: Automatic locking with adjustable jaw capacity, easy to use in one hand, simple and practical. Two sizes of wrenches in one set: 26.5cm/10.5 wrench has a jaw capacity of 14-30mm/0.55-1.18, 38cm/15 wrench has a jaw capacity of 30-60mm/1.18-2.36, work well with different nuts like prism, square, diamond nut, etc., 14-60 mm specifications can be applied to meet your different needs. These adjustable wrenches spanner also has hardened serrated teeth on its jaws. The hard teeth can bite into the softer metal of the round pipe and provide the grip needed to turn a pipe. TPR ergonomic handle secures your grip at the strongest point and keeps the user's wrist in a normal position to reduce strain and enhance productivity on the job. Tapered Crowbar Design at the end of the handle make the wrench more useful. Material: High Carbon Steel, Thermoplastic Rubber (Handle) Large Wrench - 38cm/15 Small Wrench - 26.5cm/10.5 Wrench Jaw Capacity: Large Wrench - 30-60mm/1.18-2.36 Small Wrench - 14-30mm/0.55-1.18 Measurement System: Metric Weight: 1.4kg/3.1lbs.Items from Sheng Xinshun's shop