●Made from rubber with brass nut. This well nut set is sturdy, non-deformation, durable for long time use. ●Tightening a threaded screw into the brass nut expands the insert to secure the fixing. ●Resistant to vibrations and shocks - dampens noise. Fixing in blinds, burr-free holes ●The flanged end faces outwards and holds the entire assembly in place. Useful accessory for sealing holes or isolating vibrations. ●This set of nuts is really useful accessory for sealing holes or isolating vibrations, suitable for motorcycles, kayaks, canoes, etc.