The hot weather sun hat is a lightweight, soft crowned model with a quilt-stitched brim and chin strap. The hat is lined with self material.
Military specification MIL-H-43577 covers hats made of cotton material.
Military specification MIL-H-44105 initially covered a hat made of cotton/nylon twill material dyed in a 6-color camouflage desert pattern and then different types of hot weather sun hats.