Quickun Inline Check Valve, 1/4" Hose ID One Way Return Inline Check Valve High Temperature and Corrosion Resistance Fish Tank Pump Medical Automotive (Pack of 2)

Worked great when used with 7mm silicone tube. They might be a little stuck when you get them but I just blew through mine and it loosened them up. Blocks both air and water from flowing back. Great little check valve.

Works Great. Easy install

Product arrived on time, packaged well, and installed and performs as expected.

Package didn’t arrive on time…..3 days after stated date. One of the valves works properly but the other leaks down in a few seconds. Good thing they sent two.

Item arrived in good condition and packaging. Valve required more air pressure than I was looking for. Would be great to have description of how much average pressure is required for successful valve operation.

I was amazed to see water coming out of the bucket of concentrate after I had just replaced a bad check valve in a Syphonject Siphon Mixer with External Check Valve. Had I put it in backwards? No, I could be blow through it both ways. I put the the second one in and it blew out instantly.

Works as should

The short single barb connection isn't large or long enough to have a tight leakproof fit with standard flexible vinyl line. Based on the construction, I doubt it would hold a good leakdown seal at the valve but didn't even get that far given the poor fitting connections before sending them back for a refund.