Size XL.  See can for image of actual boxers.

AI says....

The product is a unique and quirky item: Pepsi Men's Boxers in Soda Can Shaped Coin Bank. This bank, made in China, features a multi-color design and is sealed from 2008. The item serves as a clever gag gift, combining a practical function with a fun and unusual shape. Perfect for collectors of advertising memorabilia or those looking for a novelty item to add to their collection.