The HUSH Hat is designed to comfortably (and fashionably) protect your little ones sensitive hearing and softening sounds that constantly wake sleeping babies. Designed with specialized medical grade sound-absorbing foam and ultra-soft materials, each HUSH Hat not only reduces noise, but is incredibly comfortable. The HUSH Hat fits slightly different than a regular hat. It is longer in order to completely cover the infants ears, so it may require a little adjustment on your end. When placing on the hat on your babies head, first knead the foam for 5-10 seconds to warm it up. The foam has optimal sound absorption when it is warm and in contact with the skin. The warmth allows the foam to conform more closely to the baby's ears. Babies' ear placement ranges greatly so the foam is also adjustable, allowing you to position it in the best manner. If you feel the HUSH Hat is too low over the babies forehead you can reposition it by giving the back of the hat a little tug. If you have any questions, please contact to HUSH Baby. The HUSH Hat is NOT intended for all night use. Tested by Owens Corning Labs, CPSIA Compliant, Endorsed by Physicians. Medical grade foam is produced in a green energy facility. Poly jersey blend fabric is 87% Polyester, 10% Rayon, 3% Spandex. Hand wash, lay flat to dry. HUSH Hat comes is four sizes to cover newborns and toddlers up to 2 years old. The HUSH Baby HUSH Hat is sized according to the infants head circumference in inches as follows: Small: 15", Medium: 15 1/2", Large: 16", X Large: 17 1/2". HUSH Hat comes in five lovely colors: Cobalt Blue, Mulberry Burgundy, Pearl Natural White, Slate Gray, & Topaz Mint Green.