If you are using a General Pump downstream injector, you may want to consider adding this check valve setup to your arsenal. Not only does it help prolong the life of your injector, but it can also improve the strength of your chemical mix. The check valve allows you to keep fluids flowing in one direction within your high-pressure system. The maximum pressure tolerance is 5000 PSI. The stainless steel body comes with Viton O-ring. Less than 1 PSI cracking pressure. 200 degree Fahrenheit maximum temperature rating. This injector will fit General Pump 1.8 orifice, 2.1 orifice and 2.3 orifice injectors.