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 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 measuring instruments. - Widely used for tools & equipment, hand tools, automotive, replacement parts. - Fits for bicycles, locks, automotive, plastics, electronics, hardware, , fixtures, molds, toys, etc. Specifications: Compression springs include: 7 x 13mm 10pcs 6 x 12mm 10pcs 5.5 x 27mm 10pcs 9.5 x 16mm 6pcs 9 x 18mm 12pcs 9 x 35mm 8pcs 5.5 x 38mm 10pcs 7 x 19mm 10pcs Extension spring include: 5 x 10mm 10pcs 5.5 x 14mm 10pcs 6 x 10mm 10pcs 8 x 13mm 8pcs 7.5 x 17mm 10pcs 8.5 x 26mm 12pcs 8 x 50mm 12pcs (without ears) 7 x 55mm 12pcs 4 x 70mm 12pcs 5 x 34mm 8pcs 7 x 25mm 10pcs 8 x 23mm 10pcs Package list: 200 x WINOMO Extension Springs