Woman’s Velvet Casual Blazer From Saks 5th Avenue. Size medium

Please note, I bought this blazer Adam estate sale about a year ago. It says from “Saks fifth Avenue” and on the other side it says “Yves Saint Laurent” I am selling it as A Saks fifth Avenue blazer. I’m not sure if it is authentic. Measurement is 20 1/2 inches from armpit to armpit Shoulder to the bottom is 29 inches Crease of the sleeve is 24 inches I am 5’ 6 at 140 pounds and it fits me perfectly. Such a cute blazer There is no size tag, but I wear a medium Good preowned condition