Hull Gard Boat Fenders feature a unique oval design that prevents the bumper from rolling out of position. The Hull Gard combines unsurpassed softness and superior strength to provide boaters with the maximum protection available from a utility boat fender. Hull Gard’s unique oval shape adds extra protection by providing a wider, oval-shaped side that makes contact with the boat’s side so when the water gets rough, this helps push the boat away from the dock and creates space, allowing the fender to maintain its position between the boat and dock. In rough water conditions, rounded boat bumpers will continuously roll alongside the dock, potentially pushing it above the dock and risking contact and damage. All five fender sizes feature an inflation valve to easily adjust the firmness level to your satisfaction. Recommended inflation is 2 psi.