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. Simple to install - only requires a screwdriver, adjustable hinges for perfect fit, corrosion proof, self-aligning hardware. Clean with Warm Soapy Water. Made of High Impact Polypropylene Plastic. UV additive maintains original color.