1、RUBBER MATERIAL: Made of rubber material, static prevention, oil and UV resistant, heat and wear resistance, durable, long service life2、MEET NEEDS: Soft and elastic O ring, just fasten, easy to install. 270pcs O ring combination set to meet most plumbing, automotive and general maintenance needs3、LONG LIFE: The rubber construction provides seals against leaks, heat, oil, gas, water, and most silicone oils and solvents. Flexible construction and thick wall properties enable long term use4、EASY TO STORAGE: Store in a labelled and organized resealable box, saving you organizing and choosing sizes. Multiple thicknesses and sizes all in box, very convenient to use5、APPLICATION: This O ring set is mainly suitable for professional plumbing, faucet, automotive, machinery, maintenance, air or gas connections, etc.