The SMC 5720290 is a 426 Series check valve that is used to prevent potential equipment damage and contamination, as well as reducing water hammer likelihood, by eliminating back flow and maintaining constant back-pressure in your car wash systems. Designed to operate in any position. Equipped with 1/4" MNPT x 1/4" FNPT connections. Housing is made with PVC, Viton seal, 302 stainless steel spring and 316 stainless steel ball.