Strong and durable - injection molded of high-impact, chemically resistant polypropylene ergonomically designed for comfort and quality seat bumpers are molded-in for extra strength and durability, never need replacing ultra-violet protection molded into each seat to prevent color fading simply to install - only requires a screwdriver, adjustable hinges for a perfect fit, corrosion-proof, self-aligning hardware clean with warm soapy water made of high impact polypropylene plastic UV additive maintains original color.