Soft Surroundings open front cardigan sweater vest in mint green

Soft Surroundings sweater vest Open front cardigan style Sea foam, mint green color Open knit, long layering piece Has decorative buttons on back Size tag says size W, I don’t know what that means I’m listing as XL, it is a racerback style also, so armpit to armpit measurements won’t be much help Why am I even listing? Cause it’s cute and someone needs it K6