Features: Make of nitrile rubber materials, great water and oil resistance, great heat resistant, good sealing, corrosion resistant, wear resistant. Soft and flexible o rings, simply snap on, easy to install. The metric o rings prevent leaks in fuels or water plumbing, machinery, hydraulic, and pneumatics connection; provide secure seal for any oil, air, gas, and water seal application(faucet, sinks, filters). Stored in a organized resealable case saves you effort in tidying up and choosing size. This O Rings Assortment Set includes up to 1200Pcs of 24 different size of o-rings. With it, you can use it for months or even years, saving you the trouble of going to the hardware store. Specifications: Materials: Nitrile Rubber Size: As Shown in the Picture Package Includes: 100Pcs 6x1.5mm 100Pcs 6.5x1.5mm 100Pcs 7x1.5mm 100Pcs 8x1.5mm 100Pcs 9x1.5mm 100Pcs 10x1.5mm 100Pcs 11x1.5mm 100Pcs 12x1.5mm 50Pcs 13x1.5mm 50Pcs 14x1.5mm 50Pcs 15x1.5mm 50Pcs 16x1.5mm 20Pcs 17x2.4mm 20Pcs 18x2.4mm 20Pcs 19x2.4mm 20Pcs 20x2.4mm 20Pcs 21x2.4mm 20Pcs 22x2.4mm 20Pcs 23x2.4mm 20Pcs 24x2.4mm 10Pcs 25x3.1mm 10Pcs 26x3.1mm 10Pcs 27x3.1mm 10Pcs 28x3.1mm note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to difference between different monitors, the picture may not reflect the actual color.