BELL & GOSSETT 2-1/2" SWEAT THERMOFLOW INDICATOR (MODEL TFI-2-1/2) 51-170 GPM FLOW RATE FOR BALANCING WATER FLOWS WITH A B&G THERMOFLO INDICATOR INSTALLED IN EACH CIRCUIT OF A HYDRONIC SYSTEM, FLOWS CAN BE ACCURATELY BALANCED ACCORDING TO DESIGN REQUIREMENTS.Click Here for Additional Information