The 133-piece extension spring kit includes 18 extension springs of different sizes, and presents a beautiful storage box made of spring steel, which can be used for a long time. The18 extension spring sizes include:0.016"x0.16"x0.39",0.016"x0.16"x0.59",0.016"x0.16"x0.79",0.016"x0.18"x1.18",0.016"x0.18"x1.75",0.02"x0.17"x0.81",0.02"x0.22"x1",0.02"x0.22"x1.4",0.02"x0.25"x0.39",0.02"x0.25"x0.86",0.02"x0.25"x1.5",0.02"x0.25"x2.01",0.02"x0.25"x2.52",0.03"x0.31"x1.12",0.03"x0.31"x1.24",0.03"x0.31"x1.75",0.03"x0.33"x1.43",0.03"x0.33"x1.85". Features: the tensile spring has high ductility, good tensile strength, smooth, firm and flexible surface. Usage: tension spring is suitable for all kinds of repairs and maintenance of automobiles, hand tools, replacement parts, tools and equipment. Tips: the tension spring is of fine workmanship. If you have any questions when using the product, please contact us in time and we will deal with them as soon as possible.