Feature:1. Manufacturing Material: Made of high quality aluminum alloy and rubber materials, it is strong and durable, which undoubtedly extends its service life.2. Quenching and Oxidation Processing: Quenching processing, anodic oxidation treatment, it is wear resistant, not easy to rust, and has high gloss.3. Built in Rubber Sealing Ring: Built in rubber sealing ring, easy and effortless pumping, can effectively avoid leakage.4. Special Nozzle Converter: Bicycle special nozzle converter, presta valve to valve converter.5. Purpose: Installed on presta valve, it is convenient to use the valve cylinder to pump.How to Use:1. Unscrew the air nozzle sealing screw of the presta valve inner tube. 2. Install the converter of the presta valve and use air cylinder to pump. 3. After the air is filled, unscrew the converter base of the schrader valve and presta valve, and tighten the sealing screw of the nozzle. Specification:Item Type: Mountain Bike Pump AdapterWeight: Approx.4g / 0.1ozMaterial: Aluminum Alloy + Rubber Sealing RingProduct Size: Approx.15 x 9.5mm / 0.6 x 0.4inFeatures: Built In Rubber To Avoid LeakagePurpose: Installed On Presta Valve, It Is Convenient To Use The Valve Cylinder To Pump. Package List:2 x Valve And Presta Valve ConverterNote:Please allow 0‑1 inch error due to manual measurement. Thanks for your understanding.