That socket is from snap-on
check this link:
MotorWeek: Auto Basics: Goss' Garage
Does any one know the part number for it, and if snap on still sell it?

 

Just search for "shallow" Snap-on: Hand Tools, Power Tools, Tool Boxes, Automotive Diagnostics and Shop Equipment. They have dozens of different types. Those look like the flank drive type?

 

I have a full Mac set and the Snap-On ratchets like that. They used to be used for upper control arms, but now they are marketing them as low profile sockets. Search E-bay for Snap=on alignment, as they are not available from the Snap-on web site anymore.