The Sunday Afternoons Kids' Explorer Cap keeps your children cool and protected no matter where go to find adventure and lets parents rest easy knowing their children are safe playing outdoors. Made with water repellent and stain resistant nylon sun fabric with crown ventilation that sheds moisture and allows air to circulate. 1 3/4" - 2 1/2" ball cap style brim to protect your eyes from sun and rain and a full 5.5" neck cape for protecting your ears and back of the neck. UPF 50+ protection from harmful UV rays. The Smart Strap breakaway chinstrap technology uses an adjustable toggle and breakaway clip that detaches under tension. This effectively keeps hats on heads in windy conditions but easily detach at the chinstrap in case of emergency. Stroller friendly comfort. External sizing band for custom fit. Crushable brim for packing and travel. Sizing (Head circumference): Infant: 18"-20", Baby: 19.75"-21.75", Child: 20.5"-22.5", Youth: 21.75"-23".