6 Pieces One Way Inline Check Valve Bulk 3/8 Inch 10 mm ABS Plug-in Check Valve Fuel Water Gas Air One-way for Liquids and Gas

They work perfectly

Used it as a one way breather for a fuel tank to allow inflow to offset fuel flow while the engine is running but not allow constant venting, stinking up the garage. The fuel cap has a spring loaded seal if real pressure starts to build up. Works great!

Works fine. No leaks.

I used these to replace the one-way flow valves in both my and my wife's SleepMe Chilipads. These look and function identically. These valves fail pretty regularly, the same as the valves did that came in the units from the factory. I am not sure how long these are supposed to last, but I find I need to replace them about every three months or so, because something happens and the water is allowed to flow back down into the system. These are pretty cheap, and it is pretty easy to change the part in my application, so I am not going to knock them too much. Four stars because I wish they lasted six months instead of three months between failures.

Work great. I used them in a laundry to keep the detergent pumps primed.They fit perfect in the plastic hoses and no leaks.

works awesome

Replaced a broken one-way valve to prevent backwash in a water hose. Works well

Used this check valve as a backflow preventer on the discharge line on the 3/8 water softener to prevent backflow contamination straightforward installation. The cost for the amount of check valves you get is decently priced. Sizing is correct as stating in description. Being plastic should last for sometime the last aluminum one I had degraded overtime if anything changes, I shall keep this review updated.