Chloroprene rubber (CR), commonly known as Neoprene®, was one of the first commercially successful synthetic elastomers, developed by DuPont in 1931 through emulsion polymerization of chloroprene (2-chlorobutadiene). This versatile elastomer offers a balanced combination of properties, making Neoprene O-rings ideal for refrigeration systems due to excellent resistance to ammonia, Freon refrigerants, and other coolants. Neoprene also provides good resistance to moderate oils, many chemicals, ozone, UV, sunlight, and weathering, and exhibits outstanding toughness with inherent flame retardancy. Neoprene O-rings are typically black and have a recommended shelf life of 15 years when stored under proper conditions.