Got fuel or fluid flow issues? These 3/8 inch (10mm) check valves are simple but super effective solutions. You get four aluminum alloy valves in the pack - plenty for your project with spares for future needs. The one-way design stops water, oil, or petrol from flowing backward in your lines, keeping everything moving in the right direction. The aluminum construction means they won't rust or corrode, which is crucial for fuel systems. Installation is straightforward - just make sure you're putting them in the correct flow direction. They're perfect for various pipeline systems whether you're working on small engines, fuel lines, water systems, or other fluid applications. Having multiple valves means you can use them in different projects or replace several in a system at once. The silver finish looks clean and professional too. It's one of those small components that can solve big problems in your systems. No more dealing with backflow issues that mess with your equipment's performance. Keep your fluids flowing the right way with these reliable little workhorses!