Twist-Lock Couplings bodies are made of Stainless Steel and use an Acme thread to allow for easy hand tight connections, it includes a Garter spring that prevents the coupling from coming loose when in use.
Each Coupling Assy. uses a replaceable seal assembly that can easily be replaced in the field. (the 3/8" NPT and 1/2" NPT couplings use the same seal assembly.)