The Oceans East "Lil" Marlin Hat for Kids is a Grom Squad USA 5 panel trucker style hat with Snapback for adjustable fit. Size: BIG 18 months-5 years (49-53 cm) * SIZING TIPS * – Based off the average head circumference, by age (50th percentile growth chart) – Measure in centimeters around the child’s head just above the eyebrows