BIG FLASKS AND BOTTLES WILL NOW FIT IN YOUR CAR CUP HOLDER. Fits best with flasks, bottles and cups measuring 3 3/8 to 3 3/4 inches in diameter. Works best in cup holders measuring 2 7/8 to 3 7/8 inches in diameter. Fits most 32oz and 40oz wide mouth flasks and bottles including Hydro Flask, Kleen Kanteen, Simple Modern, and Mira. Even works with your 32oz Gatorade. Be sure to measure your car cup holder and Flask or bottle before you buy your adapter