A series of durable, miniature plastic relief valves from Industrial Specialties Mfg., Inc. include a unique, patented relief mechanism. Offered in 10-32, 1/4-28 and 1/8 male threads and 10-32 female threads, the valves consist of nylon bodies with 316 stainless steel springs and a silicone ball enclosed in polycarbonate housings. Colored muffler caps indicate the pre-set pressure relief spring specification.