Higher hardness can prevent safety hazards caused by slippery teeth. High-quality workmanship makes it anti-oxidation and anti-corrosion. Three-layer electroplating makes it anti-rust and more durable compatible you to use. The overall heat treatment makes its hardenability better and it is stronger. Made of screw thread steel material, it is very durable to use. There are thirteen specifications compatible you to choose from: 5.5-7, 8-10, 9-11, 10-12, 11-13, 12-14, 13-15, 13-16, 14-17, 16-18, 19-22, 22-24, 24-27. It is suitable compatible home, workshop, auto repair, car and so on. Item Name: Double Ended Wrench Material: Screw Thread Steel Product Process: Galvanized Features: High Hardness, Mirror Polished, Efcompatibletless Specifications: 5.5-7, 8-10, 9-11, 10-12, 11-13, 12-14, 13-15, 13-16, 14-17, 16-18, 19-22, 22-24, 24-27 Corresponding Head Width: 15/17mm, 18/20mm, 21/25mm, 21/25mm, 23/28mm, 25/28mm, 26/31mm, 26/31mm, 29/34mm, 31/35mm, 35/40mm, 40 /45mm, 45/50mm Size Details: 5.5-7: 11cm x 1.7cm x 0.5cm/4.3" x 0.7" x 0.2" (Approx.) 8-10: 12cm x 2cm x 0.5cm/4.7" x 0.8" x 0.2" (Approx.) 9-11: 13.8cm x 2.5cm x 0.5cm/5.4" x 1" x 0.2" (Approx.) 10-12: 13.8cm x 2.5cm x 0.6cm/5.4" x 1" x 0.2" (Approx.) 11-13: 15.5cm x 2.8cm x 0.6cm/6.1" x 1.1" x 0.2" (Approx.) 12-14: 15.5cm x 2.8cm x 0.6cm/6.1" x 1.1" x 0.2" (Approx.) 13-15: 16cm x 3.1cm x 0.7cm/6.3" x 1.2" x 0.3" (Approx.) 13-16: 17cm x 3.1cm x 0.7cm/6.7" x 1.2" x 0.3" (Approx.) 14-17: 17cm x 3.4cm x 0.7cm/6.7" x 1.3" x 0.3" (Approx.) 16-18: 19.3cm x 3.5cm x 0.8cm/7.6" x 1.4" x 0.3" (Approx.) 19-22: 21.5cm x 4cm x 0.8cm/8.5" x 1.6" x 0.3" (Approx.) 22-24: 23.5cm x 4.5cm x 0.9cm/9.3" x 1.8" x 0.4" (Approx.) 24-27: 25cm x 5cm x 0.9cm/9.8" x 2" x 0.4" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Wrench