Manufactured from chrome vanadium steel that's hardened and tempered. The long arm is particularly useful when working in confined spaces and varies in length from 65mm on the 0.7mm/0.028" through to 170mm on the 10mm/ 3/8" size. in plastic case. Features and BenefitsContents: 0.7-10.0mm and 0.028-3/8"Manufactured from chrome vanadium steel thats hardened and temperedThe long arm is particularly useful when working in confined spacesSupplied in plastic case Contents 15 x Metric keys: 0.7, 0.9, 1.3, 1.5, 2.0, 2.5, 3.0, 4.0, 4.5, 5.0, 5.5, 6.0, 7.0, 8.0, 10.0mm 15 x Imperial keys: 0.028, 0.035, 0.050, 1/16, 5/64, 3/32, 7/64, 1/8, 9/64, 5/32, 3/16, 7/32, 1/4, 5/16, 3/8