Their new locking system is only available on the extra long 3/8 drive. I talked to a very high volume dealer about 1/4 and 1/2 drives as I am interested in extra long of each drive and was told the 3/8 extra long was done out of necessity due to the old mechanism not having the strength required for the extra long version and not to expect to see it on anything else any time soon. I'm not sure I believe that, and have been trying to wait snap on out to release new versions, but its looking like I may end up going matco. I even contacted snap on directly to see if they had plans to release other drive sizes/models but they were no help.