CORISRX BEST OF YOUR LIFESTYLE Dr. Moss 2pcs Stainless Steel Check Valve ONLY for Co2 Tank,Aquarium Co2 line 4/6mm Tubing Regulator Diffuser Plants Tank

So far, they seem fine. I saw other reviewers claim theirs didn’t work but mine seem fine. If you connect them to a air pump they may not work right but under a pressurized co2 system, they work fine. I’ll update if anything changes.

I received two of these with the intention of placing them in my CO2 line to help protect my investment in my needle valve.I used some higher quality tubing when setting up my system, that has a thicker wall. This meant that getting my airline to actually fit over this barbs was exceptionally difficult. Long story short, it took me a few hours and multiple attempts to get enough line over the first barb to be sure they would even stay on. I had to grab the first one so tight I used a wrench, and when the first one failed I assumed it was because I had grabbed it so tight in the wrench that even though there was no visible damage, something inside had been broken. So I tossed it and went to install the second one.I learned from the first experience, and put my airline tubes in boiling water for a few moments to soften them up and this made the second one much, much easier to install. It still wasn't exactly easy, but I managed to get the airline to reach down past all three barbs and without squeezing the check valve that much.This second one also fails. I regularly get water siphoned back from my reactor down my air line, and it doesn't stop until it hits this check valve. It's gotten water in it now and I have no idea how long it will last like that. Regardless I'm very disappointed that both failed before ever really being used. At least it seems to stop the water once it reaches the valve, that's better than nothing, but there's no guarantee it won't cause problems moving forward.Edit: two weeks later and the water regularly siphons right through the check valve. It's useless now. It wasn't even worth the work I spent installing it.

I was sick of dealing with the cheap plastic check valves that would still leak... I picked up a pack of these metal ones and they have solved all my check valve issues. They feel well made and are hold up just great and most importantly THEY DON'T LEAK!I will be buying more to replace all my plastic check valves.

Works great looks even better.

Bit pricy but they do their job. Stops water from backing into co2 line

I was really exited to receive this product, it looks firm and strong, but for some odd reason the mechanism of the valve doesn't seem to work. And believe me I tried both ways. I really got disappointed. Maybe someone else will get lucky with it

Did not work for my application. Seller was very helpful in resolving any issues.

Purchased 4 of these for co2 and airline for an aquarium. 1 DOA, 2 failed after 2 months of use, both allowed water to backflow and one of them won't let anything through the correct direction. Huge waste of time and almost a disaster on my floor.