Stohlquist Mens Buoyancy Aids Small/ Medium Medium/ Large Large/XLarge Chest 84-100cm 102-116cm 116-130cm 33-39" 40-46" 46-52" Mens Small Medium Large X Large Chest 82-90cm 90-102cm 102-112cm 112-120cm 32-36" 36-40" 40-44" 44-48" Stohlquist Ladies Buoyancy Aids Small/ Medium Medium/ Large Bust 72-86cm 86-102cm 28-34" 34-40"