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.