Car bumpers are a vehicle's first line of defense from the bump and grind of the outside world. Car bumpers need to be able to absorb shock and offer an aerodynamic surface for cutting through air at high speed. For many decades, bumpers were made of chrome plated steel, which offers a decent amount of protection but is easily dented and quite heavy and expensive. Since the advent of plastics, car bumpers have been made almost exclusively from reinforced thermosplastic olefins. Thermosplastic is easy to form and gives way on impact, acting as a cushion to dissipate energy. Thermoplastic olefins are a type used in the automotive industry because of their energy absorbing qualities, ease of manufacture, and low cost.