Atlantic Water Gardens Universal Check Valve, 1.5-Feet to 2-Feet for Water Features Check Valves mount the pump in the Skimmer to maintain water in biological filters and keep beneficial bacteria hydrated Atlantic's Triton TR215CV Check Valve isthe first and only specifically designed for water feature use Included adapters accommodate multiple pump, skimmer, vault and plumbing options Single unions above and below the checkvalve speed removal of the valve and pump for servicing, maintenance and winterizing