Cracked distance scale tamron a007 vc 24-70 2.8
Just order one from Tamron, then take out the broken one and replace it, it needs some Contact Cement glue, just be careful don't scratch the paint around the window.
I ordered one for my Canon 300/2.8 IS ($6000 lens) and it was $24 only, so yours should be much cheaper.
|AF4_2483 Surfing the Serengeti by DaveInHouston|
from Hot Air Balloon view
|Peregrine Falcon by Psychic1|
from Best Wildlife Photo of the Week - 4