Description:
Concerned about overfilling your cup?

Perhaps the Liquid Level Indicator can give you peace of mind.

When filling a cup, the Indicator produces an intermittent tone to signal that the cup is nearly full and a continuous tone to indicate that it is full.  This allows you to  pour coffee or tea to one level and to then add milk or cream to the second level.

In both cases the liquid level indicator produces tones that make it useful to people with a visual impairment.