Neoprene® is an air-oil resistant substitute for Natural Rubber. It exhibits good oil, ozone, weather, aging, refrigeration, and chemical resistance. Its unique characteristic is its resistance to both petroleum lubricants and oxygen between a temperature range of -40-degrees F to +225-degrees F. It also affords good resilience and flex resistance. Most commonly, it is used in sealing refrigerants in refrigeration and A/C units. Standard or Imperial sizes come in fractions of an inch.