49" Giant plastic chess pieces are made of indestructible high-density polyethylene (HDPE) recycled plastic. These chess pieces are rugged, waterproof, and UV-resistant injection-molded, hollow plastic. The chess set withstands the outdoor elements very well and will retain its color. We have these sets in the middle east's heat, the far east's humidity, the rocky mountains' cold, and the salty air, sun, and sand of the southern California beaches.