Fiberglass, or glass-reinforced plastic, is a type of fiber-reinforced plastic where the reinforcement fiber is specifically glass fiber. Fiberglass is unique in its strength, yet it is lightweight, cheaper and competitive.
Applications of fiberglass include aircraft, boats, automobiles, bath tubs and enclosures, swimming pools, hot tubs, septic tanks, water tanks, roofing, pipes, cladding, casts, surfboards, and external door skins. Or in this case, it is an alternative material instead of stainless steel for less durable outdoor decorations.