I'm looking at an Omega bracelet with 540 end links.
On the clasp there is 11 in a circle but no other numbers.
I'm trying to work out if it is genuine...
The bracelet looks legit to me, but IIRC, 540 endlinks are usually for a 1098 bracelet, and that doesn't appear to be a 1098, which has extra rows of narrow links. Better photos might help. Can we see the front of the bracelet and endlinks together? They may not match.
That pairing is no good, someone just threw them together. The wide grooves in the endlinks are made to line up with the rows of narrow links in the 1098 bracelet.