Fastener seals are a composite sealing waster with a metallic carrier and a vulcanized elastomer sealing lip. They provide a static seal on flanges or threaded connections, as well as assure an ideal compression condition between housing components to prevent the destruction of the sealing lip. Fastener Seals provide the best combination of washers and O-Rings, to seal bolts and other fasteners in the assembly. For any questions, or if you can't find what you're looking for, please contact us at 1 (800) 445-7803.