BEST swimsuits ever!! So hard to find bright neon long sleeve swimsuits so you can actually see your kids in the water. They do run small so size up. My 4.5 year old average height, very thin little girl fits perfectly in the 5-6yr size and my 2.5 year old tall, average weight little girl fits perfectly in the 3-4yr old size. Wish they had a long sleeve top/swim short sets for my boys too!!