Check the listing for details. FlowVis GPM Flow Meter Valve for 2" & 2.5" Pipes | FV-2 (566821). Color: Black, Condition: New. Listed at 123.95 USD. FlowVis GPM Flow Meter Valve for 2" & 2.5" Pipes | FV-2 (566821) FlowVis GPM Flow Meter Valve for 2" & 2.5" Pipes (FV-2) FlowVis is a fully functioning Check Valve, as flow increases and decreases, the Check Valve's flapper swings within its range of motion. A specifically designed calibration spring, indicating arm, and an extended height valve body lid, constitute the fundamentals of the FlowVis design concept. FlowVis is available in two configurations A retrofit kit that installs to a pre-existing Jandy or Praher 2" x 2.5" Check Valve assembly A complete pre-assembled Check Valve assembly with FlowVis Unlike other Flow Meters, the position in which FlowVis is installed (horizontal, vertical, or relative to elbows and tees), has virtually zero effect on its accuracy. Features Superior energy efficiency Better system filtration Better system filtration Increased heating efficiency Creates more even chemical dispersion Reduced maintenance needsFlowVis GPM Flow Meter Valve for 2" & 2.5" Pipes | FV-2 (566821) FlowVis GPM Flow Meter Valve for 2" & 2.5" Pipes (FV-2) FlowVis is a fully functioning Check Valve, as flow increases and decreases, the Check Valve's flapper swings within its range of motion. A specifically designed calibration spring, indicating arm, and an extended height valve body lid, constitute the fundamentals of the FlowVis design concept. FlowVis is available in two configurations A retrofit kit that installs to a pre-existing Jandy or Praher 2" x 2.5" Check Valve assembly A complete pre-assembled Check Valve assembly with FlowVis Unlike other Flow Meters, the position in which FlowVis is installed (horizontal, vertical, or relative to elbows and tees), has virtually zero effect on its accuracy. Features Superior energy efficiency Better system filtration Better system filtration Increased heating efficiency Creates more even chemical dispersion Reduced maintenance needs