Maintenance free. Extremely durable recycled rubber will not warp, crack or rot. Withstands wide temperature extremes. Painted with polyurethane yellow reflective paint. Built-in cats eye reflectors for added visibility. Two 1-1/4 in underside channels allow for cables and provide drainage. 48 in speed bump requires 3 spikes, 72 in speed bump requires 4 spikes. Good for weights up to 6000 lb.