These are really nice slippers, but beware of the sizing! I ordered a size 9M for my husband who wears a size 9 shoe. They were WAY TOO SMALL. In fact, they just fit me and I wear a size 7-1/2 to 8 narrow in women's shoes! It's not worth it to send them back to Amazon. The shipping to get them back for a refund would probably be near the purchase price, so I'm just keeping them for myself. Only problem, I had to take my husband to J.C. Penney & buy ANOTHER pair of slippers for him. So, I ended up paying for 2 pair of slippers instead of one. I would allow AT LEAST 2 ADDITIONAL SIZES when ordering these slippers for your guy!