10AC couplings are produced in a durable natural Acetal thermoplastic and the 10PP couplings are produced from medical grade,gamma sterlizable polypropylene, the Acetal couplings are resistant to most mild chemicals and are manufactured to be trouble free for many years of service while the Polypropylene couplings offer greater chemical resistance. They are imtuitive to use and make an audible click when coupled with their mew and improved “Easy Grip Barrel”Both 10AC amd 10PP Couplings interconnect with each other as well as other similar industry twist lock type couplings.