- Professional set of 420 O-rings made of nitrile rubber (NBR), covering 32 popular sizes from 3 to 50 mm inner diameter - High-quality NBR material, resistant to acids, gasoline, grease, UV rays, and high temperatures, ensuring long service life - Perfect for sealing in automotive, plumbing, valves, engines, faucets, flanges, electronic equipment, and household appliances - 70 durometer hardness, optimal for preventing liquid and gas leaks in industrial and domestic applications - Practical storage box with clear identification of each size, making organization and transport easy - Versatile solution for professional repairs and daily maintenance in workshops, homes, and businesses