BottlePro Max (3rd generation) is our new cup holder adapter that is more versatile and fits better with more bottles and cup holders. BottlePro Max fits most bottles between 2.5" and 4.25" diameter, including most Hydro Flasks, Nalgenes, YETIs, and other similar bottles. Compatible with most bottles ranging from 12 to 48 ounces, including Hydro Flasks, YETIs, Iron Flasks, Takeyas, Simple Modern, Nalgenes, Fifty Fifty, ThermoFlasks, Klean Kanteens