Specifications: Pure copper material, not easy to rust or corrode. With gasket ring, no leakage, ensure tightness. It will increase tyre life, lower fuel consumption and increase driving safety. Perfect item to have in your bike puncture repair or tool kit, if you have Presta valves (long thin screw type on racing road bike/and now on many mountain bikes and even some children bikes such as Isla bikes) and you need to use a Schrader pump (car valve) as used in garages and on most household foot pumps. Quality precision made, these are constructed from brass and have a small rubber seal, which makes refilling tubes more efficient as gives some seal. Even if you lose the seal, they will work if you use a compressor or pump fast! Type: Presta to Schrader Valve Adapter Converter Material: Copper, Rubber Quantity: 10 Pcs Features: Bike Accessory, Adaptor Cap, Durable, Good Tightness Size: 1.7cm x 1cm/0.67" x 0.39" (Approx.) Note: Due to the light and screen setting difference, the item"s color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 10 x Presta to Schrader Valve Adapter Converters