This is a youth size 4. It was worn by a 4 -5 year old. Perfect For The Beach Or The Lake, This Ideal Wetsuit Simultaneously Keeps Toddlers Warm And Also Protects Them From The Sun Backzip System Provides Easy Entry And Exit With A Water Resistant Closure Ultra Stretch Neoprene: Incredibly Soft Premium Material Has Superior Feel, Flexibility, And Provides Unparalleled Comfort Flatloc-Stitched Seams Are Very Durable And Allow Toddler To Enjoy Playing In The Water Despite Chilly Temperatures Wetsuit Comes In Various Vibrant Color Options Description The newly upgraded Reactor-2 is engineered for performance in a value driven package. A perfect combination of stretch and durability. Fresh colors and graphics with style that's built to last.