With ABS, glass-filled, injection-molded plastic outer construction, these ramps are strengthened with 6061-T6 aluminum-reinforced inner rails that rate the ramp at over 500 lb. Design includes exclusive center traction-ribbed beam for easy non-slip loading. Self-lubricating, folding hinge has a lifetime replacement limited warranty from the manufacturer against bending or breaking. Ramp is extremely lightweight at only 11 lb. Hinged, replaceable lower plastic feet work at any angle. Center handle provides easy handling and folds in half for easy transportation and storage. Replaceable soft rubber bottom tongue plate helps eliminate excess sliding when loading. A two-year limited warranty against bending or breaking is included.