CV6R

Good quality check valves. Only needed one but for the money got a load of spares! Functions as you would expect!

The quality is good especially when you consider the price point. Recommended A***

Work well for water as well as air. The halves of the body screw together, and one of the six supplied admitted air through the join. A bit of solvent glue on the threads fixed that.

Ideally suited to pond air pump setup.

Slightly disappointed with these. Though they fit well on to airline tubing there is restricted airflow which reduces the efficiency of my air driven filters.

so far these have been amazing

The previous check valves that I was using kept coming apart from the airline. Which isn't great as then nothing is stopping water from going everywhere. These are great though and fit nice and tight so that you don't have that worry.

Super speedy service, multiple pack for multiple tanks

I only had to cut the hole open on all but 1 of them. Not a super big deal it's as easy as taking them apart and popping a toothpick and then a chop stick through the little silicone pieces. Lost a star because honestly I don't feel like I should have to do this it should have been done already since that's kinda the point is for air to go through them. After that they are exactly what ordered.

Here is an honest review from a verified purchase. I have been keeping aquariums for 40 years. These are among the best valves I’ve had. They work perfectly. Any review that says otherwise was written by someone that doesn’t know what they are doing or they were using them wrong. Simply slide a paper clip or toothpick into the opening and gently open the valve before connecting. After all you want a good seal to avoid water back flow. The air has air flows beautifully. They are easy to connect using some warm water on the tubing. They have nubs to keep the hose on. These are great valves. Don’t pay attention to negative reviews.

Waste of money, really bad design. They restrict the air flow greatly.

Item: Pawfly Aquarium Check Valves Con: ALL of the six units excessively reduce the air flow; therefore I believe that these valves will reduce both oxygenation of my 5 gallon aquarium and the life of my strong, air pump.

I found some that were cheaper immediately after I ordered these. But I had to choose these. Good quality, Does the job... I only needed 2, but whatever..maybe ill have more pumps one day.