The Fury features a light weight construction with 4 way stretch Flex-Span poly fabric. This Fabric is long wearing and fade resistant. Inside our Stretch-Light lining fabric surrounds him in comfort. No rash here! It has a unique 9 panel design allowing freedom of motion for busy little bodies. The split back panel design allows the Fury to fit snuggly and securely. The Fury also features a split wedge side panel design for increased flexibility. The Fury vest is made with our best PVX and PVE flotation foams. Both are US Coast Guard approved lab tested and certified for low water absorption and long life. The stretchable PVX foam compound makes this vest extra comfortable secure and safe! While the Extra light PVE foam provides extra flotation. It's designed to deliver locked in security with a wide range of motion. Wide arm openings and narrow shoulders lets him move in comfort. Fully turned seams are smooth and comfortable. Youth size fits 50-90 pound children.