• High-quality material: Rubber O-ring, using commercial-grade nitrile rubber material (NBR, Buna-N), is waterproof, oil-resistant, and has good sealing performance. • Easy to use: Flexible O-ring that is easy to install. Stored in a sturdy transparent plastic box with a label for easy storage and transport. • Wide application: The metric rubber O-ring can provide a secure seal for oil, air, gas, and water sealing applications (faucet, sink, filter). Prevents water leaks in fuel pipes, mechanical maintenance, hydraulic and pneumatic systems. • The package contains: M3*1, M4*1, M5*1, M5*2, M6*2, M7*2, M8*2, M9*2, M10*2, M12*3, M13*3, M14*2.5, M17*2.5, M18*4, M20*2, M25*2.4, M22*2, M27*3.