DescriptionThis 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- Color: Silver- Material: Spring steel - Size: 4.50X0.80X0.80cm/1.77X0.31X0.31in- This item is spiral springs that offer resistance to a tension force, or load, applied along the axis of the spring.- Used for automotive engines, major appliances, medical devices, electronics, and sensitive measuring instruments. - Flexible springs are both sturdy and springy for the right amount of tension. - Includes plastic case with size chart on lid to keep springs organized for the next time you need. - The different specifications of different sizes to form a package,so that you no longer run around for multiple specifications.