【PREMIUM NITRILE RUBBER】Crafted from black nitrile rubber NBR, these rings deliver reliable oil, heat, and wear resistance, making them ideal for automotive mechanics handling engine maintenance in garage workshops. 【VERSATILE REPAIR KIT】Engineered for DIY homeowners and professional plumbers, this set provides immediate solutions for fixing under-sink kitchen faucet leaks and bathroom shower hose drips, ensuring tight seals in seconds. 【ORGANIZED STORAGE CASE】Packed in a clear 24-compartment box with a detailed sizing chart, this kit allows busy technicians to find the right ring instantly during urgent maintenance tasks in cluttered service van s. 【PRECISION SIZE VARIETY】With 1200 pieces organized across 24 distinct sizes from 0.6 x 0.15 cm / 0.24" x 0.06" to 2.8 x 0.31 cm / 1.1" x 0.12", you always have the exact fit for mechanical valves and pressure pipes. 【RELIABLE SEALING SOLUTION】Featuring high elasticity and resilience, these black rings prevent leaks in pneumatic tools and garden hose connections, offering reliable performance under pressure in home workshops. Package list: 1x 1200pcs Black NBR O-Ring Assortment Kit 1x 24-Compartment Storage Case