1Made of Alloy Steel: Our double ended self tightening wrenches are made of excellent alloy steel with excellent craftsmanship. 2Wear Resistance and Sturdy: This double end self tightening wrench is hard, wear resistance and sturdy, and can withstand high strength use. 3Applicable Specifications: Our double ended self tightening wrenches are suitable for standard nuts and bolts from 3 to 17mm and are widely used. 4Easy to Carry: The overall weight of the double ended adjusting universal self tightening wrench is light and very easy to use, you can take this wrench with you at any time. 5Scope of Use: The double ended universal self tightening wrench is suitable for home improvement, construction, carpentry, repair of bike, car or motorcycle, etc. Item Type: Double Ended Universal Wrench Material: Alloy steel Working Range: Approx. 3-17mm or 0.12-0.67in Total Length: Approx. 146mm or 5.75in Thickness: Approx. 3.5mm or 0.14in 5 x Self Tightening Wrench