Non Return Valve made from plastic for air hose 4/6 mm. The Non Return Valve protects your air pump against back flow of water. Not usable for CO2-systems..
- Andreas H. wrote about Non Return Valve for Air Hose in 2018:
The valve does what it's supposed to do. Stops water from leaking back to the air pump. It has less resistance than some other I have tried = less noise from pump.
Price is awesome!