It’s a silicone band that fits over a bottle or glass. Inside, an accelerometer, which tracks the band’s movement, knows when it’s been a while since you’ve taken a sip. Go more than 30-40 minutes without some H2O, and when you’re nearby (the band’s sensors will know that), Ulla’s light will blink.
Several of us tried it out here at Grommet headquarters, and were grateful for the reminder to stay on track to drinking our eight glasses a day.
Put Ulla in place, and you don’t have to do anything else. Just drink.