79190 has sapphire crystal. The crown should be Tudor - not Rolex. Could be the parts bin effect though. Movement should be ETA 2824-2.
Looks legit, but I've seen a lot of fake Tudor Subs. If I were buying, I'd check to see if the serial maps to 1995 or later - or close to that date. Also check to see if the movement is correct. Proceed with caution?