Water Trackerz allow you to easily track your water intake. To track your water, place Water Trackerz on your favorite water bottle with a single color facing outward (teal color). When you finish drinking a full bottle, flip the first band to reveal the alternate color. Refill bottle, drink, flip and repeat. (Water bottle not included) Fits most reusable water bottles. Band circumference is 23 cm. Fits bottles greater than 23 cm in diameter. Dishwasher safe.