Snap-On Tools is a tool manufacture and distributor, they service Professional shops, to sell there tool line. They are geared toward the Professional and distribute there tools off a truck that makes stops at service center's once or twice a week. They invented the removable socket, hence the name Snap-On. Before this invention the socket was a one piece speed wrench, so you had to have one for every size (5/16", 7/16", 1/2" etc.) So now you had a speed wrench with removable sockets that Snapped on and off. This saved considerable space and weight in the tool box.