The Natural Canvas Sun Walker Sun Hat. Offering UPF protection with a full coverage brim. This hat is made with a natural cotton canvas base and offers several choices in a secondary color. The canvas has been preshrunk. The adjustable cording accommodates individual size variations in each of the offered sizes of small, medium, and large, a full size range that is sure to fit all heads. To determine your size, measure the circumference of your head just above the ears and across the middle of the forehead. Match the measurement to the corresponding size as listed. If in doubt buy the size larger. Each size allows 2.5 cm (one inch) wearing ease. If you require further information please contact DCP Designs for a zoom appointment.