All Dolphin roto-molded fenders are manufactured from the best quality marine grade vinyl resulting in superior strength, cushioning and a high gloss finish. Dolphin fenders have been tested for many years in various marine environments worldwide. Dolphin fenders resist deterioration from mildew, gas, oil, seawater and bacteria and have built in ultra violet inhibitors. All fenders include an inflation valve to allow for adjustment for the desired level of firmness. Dolphin Twin Eye fenders feature specially reinforced heavy-duty integral lugs for added strength and longer durability, these fenders provide maximum protection and value for your dollar.