This item is spiral springs that offer resistance to a tension force, or load, applied along the axis of the spring.When a load is placed on an extension spring, making it longer, the spring pulls back against the load to return to its original length.These springs are used in a variety of applications, including automotive engines, major appliances, medical devices, electronics, and sensitive measuring instruments.Features- Brand: WINOMO.- Color: As shown.- Material: galvanized steel.- Size: 20.8 x 10.6 x 3 cm/8.2 x 4.2 x 1.2 inch (Box size).- Length: 10 - 79.5mm/0.39-3.13 inch.- Replace rusted or missing springs with these strong steel springs in any shop or household application.- Versatile set includes a wide range of sizes and 200 pieces for shop and home repairs- Used for automotive engines, major appliances, medical devices, electronics, and sensitive measuring instruments.- Widely used for tools & equipment, hand tools, automotive, replacement parts.- Fits for bicycles, locks, automotive, plastics, electronics, hardware, switches, fixtures, molds, toys, etc.Specifications:Compression springs include:7 x 13mm 10pcs6 x 12mm 10pcs5.5 x 27mm 10pcs9.5 x 16mm 6pcs9 x 18mm 12pcs9 x 35mm 8pcs5.5 x 38mm 10pcs7 x 19mm 10pcsExtension spring include:5 x 10mm 10pcs5.5 x 14mm 10pcs6 x 10mm 10pcs8 x 13mm 8pcs7.5 x 17mm 10pcs8.5 x 26mm 12pcs8 x 50mm 12pcs (without ears)7 x 55mm 12pcs4 x 70mm 12pcs5 x 34mm 8pcs7 x 25mm 10pcs8 x 23mm 10pcsPacking list200 x WINOMO Extension Springs