Audible/Vibratory liquid level indicator
Ideal for making a cup of tea or coffee with milk. Place the device on the side of a cup and it will let you know when the liquid has reached the top through a series of audible beeps or vibrations. Can also be used as a single level sensor such as for non-mixed drinks. Handy magnets on the back of the unit allow for easy storage on fridge or other metal object.