The Hillman Group 290259 1/4 x 5/8-Inch - OD Bonded Neoprene Washer, 100-Pack Product Description Bonded Neoprene Washers (also known as sealing washers and cushioning washers) are a specialty washer designed to create an airtight seal between the bolt or screw and the hard surface. The washer spreads stress and strengthens the joint for a high torque application while the rubber washer cushions the joint against the hard surface. From the Manufacturer Bonded Neoprene Washers (also known as sealing washers and cushioning washers) are a specialty washer designed to create an airtight seal between the bolt or screw and the hard surface. The washer spreads stress and strengthens the joint for a high torque application while the rubber washer cushions the joint against the hard surface. Features Used to prevent leakage, distribute pressure of the bolt or screw and also make a great cushioning agent to help with vibrations Applications Include Aircraft, Auto, Marine, Railroads And Railroad Equipment, Zinc-Plated For Moderate Corrosion Resistance From The Brand Name: Hillman USA SHIPPING estimates delivery times and we work to get your item to you as quickly as possible and within those times, but please know it may take slightly longer than the estimate.