The Stohlquist Fit System features Graded Sizing™ for the best fit and lowest footprint possible for the widest range of body types. They've fine tuned each individual size, and sculpted the foam footprint and thicknesses to provide an optimized fit for the most comfortable PFD for people of all sizes. This allows them to fit younger, smaller framed paddlers up to larger adults in the same style vest, while offering the same amount of mobility and a low-profile fit across the entire size range