A reader informed me that there are actually two different versions of the Leica Super-Elmar-M 21mm f/3.4 ASPH lens (product number 11145). Here are the details:
The above picture of the new Leica Super Elmar M 21mm f/3.4 ASPH lens ($2,995.00) is from the day it was announced. The current picture of the same lens on Leica’s website has a slightly different design (bigger diameter just above the bayonet, ignore the lens hood):