An UltraZap 50mm flapper check valve is a one-way fitting that lets water flow in a single direction and closes to stop backflow when the pump cuts out. It’s a cheap, effective way to protect a system: keep a pond from draining back down a return line, hold water in an aquarium or fish tank plumbing run, or stop dirty water washing back into the clean side of a filter.

Good to know:
– 50mm size, for 50mm PVC pipe runs
– One-way flapper design prevents backflow
– Glues into the line with standard PVC fittings
– For pond, aquarium and fish tank plumbing