Opa Cove's Sea Squirts Swim Assist Vests are fun to wear and kids love to wear them. Designed with 3 removable flotation panels that provide help with swim instruction progression (remove them as the swimmer masters each level). The scientifically adjusting size location of the flotation panels (compared to other vests) successfully balances a child's center of buoyancy and reduces forward tipping for greater control/stability when swimming. The arm-hole sizing insures a proper comfortable fit so the strap between the legs doesn't have to be too tight. Sturdy Grab Me Fin and professional neoprene construction make this a comfortable and fun swim assist vest. Warning: this product is intended for use as a swim training device to teach more advanced swim skills under constant adult supervision. Measurements are as follows; Small: 19-22" chest, Medium: 22-24" chest, Large: 24-26" chest. The Swim Assists tend to run small, so if your child's measurement places them between sizes, we recommend choosing the larger size! Patent and Patent Pending.