The number identifier is something Nike does with nearly every model. Pegasus 33, Lebron 13, etc.

The only model I can think of from the top of my head tha differs is the Air Max line. Went from Air Max 1 to 90 and now we're at 2016

So, what do you have in

11.5-12?

So, what do you have in

11.5-12?