I have owned a few men's clogs over the years (even significantly more expensive ones), but without a doubt, these are the most comfortable clogs I have ever tried on. The optional use of the back strap is a plus. The strap length is adjustable (buckle). The strap can be left 'up' or even easily removed if you so wish (snaps on and off).
The lining is so incredibly soft...Great if you wear the clogs barefooted. All in all..superb!

As for size. I never order shoes from an online seller unless the seller provides for free shipping both ways because shoe sizes do differ even if labeled size 'X'.