Size Guide - Our UV-protective collared top protects your little cuties in style. UPF 50+ certified, it has three snaps that make it easy to put on. Soft and breathable, with maximum sun protection, it is super practical so you don't have to spread cream on your kids every five minutes. Plus, kids love swimming with it! The must-have of the summer! If you are unsure between two sizes, choose the larger of the two.