Fashion meets function! Just soak in water, ring it out and pop it on. The brim shades and protects your dog's eyes, and the absorbant mesh fabric releases body heat as the water evaporates. Ear holes allow plenty of circulation too.
To size, measure circumference of your dog's head, from under chin to top of skull and all the way around.
Small: 10 "-14"
Medium: 13 "- 15"
Large: 14 "- 17"
XL 16 "- 19"