This replacement flow meter is suitable for stainless steel manifolds. These flow allow the installer or operator to the flow through each circuit. By looking at the number of gallons per (GPM) entering each loop of the radiant heating system, you can use the gate valve and this flow meter to effectively balance the flow. It is important to balance your circuit so that you can heat the floor evenly. Flowmeter interface: G1/2 thread Adapter: G1/2 to G3/4 Colour: Red Material: brass + stainless steel Package Contents: 1 x Flowmeter 1 x adapter Only the above package content, other are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real . The measurement allowed is +/- 1-3cm.