About Us Multi-Purpose 225PCS Rubber O-Ring Assortment Set Gasket Automotive Seal Kit- 18 most popular sizes used in mechanical seals. Features: ✨ Material: Made from Nitrile Rubber (NBR), meets a work temperature range from -49 to 330 ℉. Good resistance to oil,water leaks and UV. ✨ EASY TO USE: Stored in an organised dividing plastic box, it is easy to choose the size you need and simply snaps on for portability and easy storage. ✨Applicability: Mainly used for general maintenance needs in automobiles and plumbing to provide provide a good seal such as taps, water pipes, sinks, hydraulic fluid, pumps, boats, kitchens, bathrooms,air conditioning and more. Specification Material:Nitrile Rubber(NBR) Size: 225 pieces (18 popular sizes) O-Ring gaskets, size is inner diameter x thickness, 4*1 means: inner diameter is 4mm, thickness is 1mm. 3*1mm * 20pcs 4*1mm * 20pcs 4.5*2mm * 20pcs 5*2mm * 20pcs 6*2mm * 20pcs 6* 2.5mm * 20pcs 6*3mm * 20pcs 7*2mm * 20pcs 8*2mm * 20pcs 9*2mm * 5pcs 10*2mm * 5pcs 12* 3mm * 5pcs 13*3mm * 5pcs 14*2.5mm * 5pcs 17*2.5mm * 5pcs 18*4mm * 5pcs 20*2mm * 5pcs 22*2mm * 5pcs Box size: 6.85*3.88*0.88inch If you are not satisfied with our products or have any questions, please feel free to consult our customer service staff. Our customer service staff will be online 24 hours a day. Finally, we wish you happy shopping!