Bottle Pro is the first car cup holder adapter designed specifically to fit larger water bottles such as: -32oz Nalgenes -32oz and 40oz Hydroflasks -40oz Klean Kanteens -32oz Gatorade bottles In general, Bottle Pro works well with any bottles that are about 3.5″ to 3.8″ in diameter. If you’re not sure if your bottle will fit, feel free to ask us. We’ll look into it and get back to you as soon as possible. Bottle Pro also has a 1″ opening on the side to accommodate handles on travel or coffee mugs. Please email us if you have any questions!