The Perfect Bungee Heavy-Duty Bungee Cords are made out of Flexa-Pure. Flexa-Pure is a proprietary polyurethane that is UV-resistant, chemical-resistant, fuel-resistant, oil-resistant, and is tested to keep working in the harshest weather conditions. This 8-piece heavy-duty Poly Bungee Cord Variety Pack includes: Two 12" Heavy-Duty Poly Bungee CordsTwo 18" Heavy-Duty Poly Bungee CordsTwo 24" Heavy-Duty Poly Bungee CordsTwo 30" Heavy-Duty Loop End Poly Bungee CordsNOTE: All Perfect Bungee Cords can safely stretch up to 2x their original length. Tested to keep working in the harshest weather conditions Includes two each of 12"", 18"", 24"", & 30"" bungee cords | The Perfect Bungee 8-Piece Variety Pack