Product Description： Package Included: 4 pcs Made of high-performance new engineering material casting technology, Specially designed for tire valves, tight fit. Warm Notice: To prevent the metal valve cap from fusing with the tire valve stem, please apply grease lubricant onto the threading of the valve stem prior to installation. Aluminum valve caps would be locked if they stay in acid or alkaline liquid environment for a long time, please loosen them at least once per month. Service: If you have any questions about the product, please contact us in time, and we will provide you with satisfactory solutions.