Strength: Steel, this product have excellent durability and resistance Opening design: The Wrenches head adopts opening design, which is for quickly placing and screws and other fasteners and improves work efficiency Large opening design: The 8 / 10 / 12 / 15inch adjustable Wrenches suitable for handling large-size screws and fasteners, providing better operability Adjustable function: The Wrenches have adjustable characteristics, allowing users to flexibly adjust the opening distance of the Wrenches according to different need to adapt to different specifications of fasteners Ergonomics: The handle of the product conforms to the ergonomics principle, which is comfortable to hold and easy to operate, reducing the fatigue of users, Manufacturer: Kaeltsyn