This compact, lightweight device has three metallic probes which indicate two separate liquid levels within a cup or mug by triggering audible alerts. The first alert tells you when to stop adding hot water if you also want to add milk; the second alert tells you when the cup is nearly full. The device can be used on most cups and mugs, as well as glasses, jugs and (cold) cooking pots. Store your Liquid Level Indicator on the fridge door, using the built-in magnets, so it’s always easy to find when you need it. You can use a damp cloth to clean the probes, but please note that the unit must never be immersed in liquid as it is not sealed and the electronics will be damaged. It is recommended that you test the unit with cold water before each use, to ensure the device has sufficient battery capacity to operate properly. The easy-open battery drawer makes changing the battery simple and a beep confims it is fitted correctly.