Effective Backflow Prevention: The check valve is expertly designed for pumps to prevent medium backflow, ensuring the safety of your equipment and the stability of your system. Ideal for chlorine pump applications, this valve maintains optimal operation. Broad Compatibility: This 1/4-inch check valve is compatible with a wide range of Sten-ner pumps, including the 45, 85, 100 & 170 Series, Classic Series, Single Head, S420, S128, S10P, VX, SV, and S Series. Note: It does not fit S40, S4V, S44, S4M, S50, S54, S5V models. Simple Installation Process: Designed for hassle-free installation, this check valve can be easily fitted by tightening the connection according to the pump's inlet and outlet threaded ports. The included pump hose ferrule and valve simplify maintenance of your peristaltic pump. Color: Black Material: plastic Package Contents: 1* Check Valve Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.