[Main material] The check valve is made of high quality stainless steel, sturdy, more durable than the common plastic valve and has better performance. [Easy to use] Each one-way valve is marked with an indicative arrow, which clearly indicates the direction of fluid flow. The valve can effectively prevent fuel from returning to the fuel tank and keep it in driving. [Function] Stable characteristics, high reliability. Easy installation and replacement. Prevent fuel from returning to the tank and keep it online. [Package include] You can get 2 check valves, check valve hole diameter: 12mm, suitable for 12mm fuel tube. [Widely application] Aluminum valve can be used for carburetors and low pressure fuel systems. It is widely used in cars, boats, caravans, helicopters, boats, motorcycles, etc. Suitable for gasoline, diesel, oils, water and other fluids. Features: Made of stainless steel and durable, to prevent corrosion and rust, have an excellent finish, the surface is carefully treated. Specification M12 Multiple use: Suitable for low pressure carburetor and fuel systems. For use with gasoline, diesel, bio / vegetable oil, paraffin / kerosene oil, etc. Specifications: Product name: One-way fuel check valve Product size: Diameter 12 mm Connection type: Flange Color: Silver Material: Stainless steel Package included: 2 * One-way fuel check valve Notes: There might be some deviation due to manual measurement.