Sargent & Greenleaf 826c
is because the seller said the one I bought from him did not however I did some research myself & according to the S&G catalog it can be
I am only asking this as the two keys supplied with the lock are different
& assumed one would be a control key I asked the seller if one of the keys had control stamped on it he said no
perhaps Hallischarmers can help me as I noticed that he had one posted in his lock pics
here is a pic you can see the keys are not the same help........