Arctic Hayes U-Flow Water Measuring Cup Dual-Scale Flow Rate Tool for Plumbers The Arctic Hayes U-Flow Water Measuring Cup is a smart, innovative tool designed to help plumbers and installers measure water flow rates with speed and precision. Exclusive to Arctic Hayes, this clear, see-through flow cup allows you to easily monitor flow measurements from both sides, in either litres or gallons per minute. With a robust, heat-resistant construction, it’s ideal for new installations and flow rate testing during system setup. The cup is also compatible with the Arctic Hayes AH02 stem thermometer, allowing temperature and flow to be tested together. Whether you're balancing heating systems or checking hot water performance, this flow cup is a must-have on every toolkit