I would give it a small large, more of size 36"-40". This vest is not a Coast Guard Approved PFD life jacket.
You still need the required CGA PFDs for your boat. This item is in the category "Sporting Goods\Water Sports\Swimwear & Safety\Life Jackets & Preservers". The seller is "closeout-dude" and is located in this country: US. This item can be shipped worldwide.