It should fit snug, yet comfortably for kids to have full range of motion while swimming. The one shown in the video is a size medium/large, designed to fit children 3-4 years old from 26-40 lbs. A small/medium size is also available for 2-3 year olds.
Stack and Learn & Stacking Cups
Design & Build Water Blocks
Stack & Squirt
McCoy's Brainy Ball
Disney Princess Swimming Adventures Ariel
Deluxe Beach Bag
from American Plastic Toys Inc.