The Hydr-8 GALLON is a 32 ounce, air-insulated water bottle marked with short term time goals to help you reach your water intake goal of 1 GALLON of water every day. A gallon a day seems like a lot, but a cup every hour? Not so bad! The GALLON has 4 columns of time goals. The time slots are marked with a goal of 8 ounces every hour from 7am - 10pm. To start, simply fill your water bottle to the top each morning. Drink enough water by each time mark that your water level is at the corresponding line for that time indicated on the bottle. Fill your bottle each time you drain it and keep hitting your time goals and you will get your 128oz (1 Gallon) every day!