97%Cotton 3%Spandex Size: Medium best fits for 55-57cm, 6 7/8- 7 1/8, 21.6-22.5; Large best fits for 58-59cm, 7 1/4- 7 3/8, 22.8- 23.2.With an adjustable tape built in sweatband to help find the best fit. Sunscreen:Outdoor hat offer high UPF50 sun protection with 3.5 wide brim, sun blocker function make it suitable to use as a outdoor hat for hiking, hunting, camping, or useing as a garden hat; Invisible Ponytail Hole – Perfect to pull your bun or ponytail through on hot summer days; plus the opening is basically not visible, so it just looks like a regular fashionable sunhat when you don’t use the ponyhole Portable and Stylish: Lightweight and breathable material makes this sunhat comfortable. The mesh opening allows air flow well in, so it will not overheat in the summer. Adjustable chin cord strap keeps this cooling Sunscreen Hat secure for windy days. Crushable and Packable: An essential accessory for your Outdoor Travel/Holiday/Beach playing. Folding Packable design for easy storage in a handbag or backpack when it is not in use. Convenient carrying along!