Color is Changable Automaticaly.
It glows automatically when drinks are added, turns off when there is no liquid left. Washable and Durable
First there were party drinks, then there were body lights / blinkes, now we bring you our EZ LED Light-Up Flashing Beer Mug, the ultimate light-up party and bar favor! Imagine holding a luminous beer mug in your hand, where the whole mug, and the beverage inside, spin with many colorful lights! This light-up beer mug is made of a high quality, safe, clear acrylic, with replaceable batteries