Feature: 1. 60HRC: Self tightening spanner is made of high hardness steel forged to 60HRC, impact resistant and wear resistant. 2. SAVE POWER: Length is 270mm, thickness is 8mm, clamping range is 8 to 22mm, suitable for nuts of different sizes, 14 to 22mm. Utilizing the principle of leverage, it saves more power. 3. PREVENT SLIPPING: Universal self tightening wrench is designed with unique teeth and protection threads, smoothly to use and not easy to slip. 4. EASY OPERATION: Simply align the hole of the wrench with the nut and you can do many jobs without changing to a different size wrench. 5. APPLICATION: Double ended wrench is suitable for home decoration, construction, carpentry, automotive, bike, motorcycle repair and home maintenance. Specification: Item Type: Double Ended Self Tightening Wrench Material: Steel Total Length: Approx. 270mm / 10.6in Applicable Range: Approx. 8-22mm / 0.3-0.87in Usage: Wrench for Holding Nuts of Different Sizes. Applicable People: Outdoor Enthusiasts, Automobile Repairers, Home Users. Package List: 4 x Double Ended Self Tightening Wrench