The Xylem-Bell & Gossett 117414LF CB-1/2 Circuit Setter is a manually adjustable valve used in hydronic heating and cooling systems to regulate water flow. It features a half-inch diameter connection and can precisely control flow rates between 0.5 and 7 gallons per minute (GPM). Made of durable brass, it can withstand pressures up to 150 psi and temperatures reaching 250°F (121°C). https://www.partshnc.com/117414lf-xylem-bell-gossett-cb-12-12-circuit-setter