Ronix Party Impact Vest"IF IT ZIPS, IT FITS"All life jackets CGA and impact NCGA vest should fit very snug, like a compression shirt. These vests will stretch out after a couple uses and fit more comfortably. If your life jacket or vest zips up too easily without any effort, chances are it is too big and will ride up off your shoulders in time. SIZE CHEST SIZE (IN CM) Small 31 34 79 86 Medium 34 37 86 94 Large 37 40 94 102 1X Large 40 43 102 109 2X Large 43 46 109 117 3X