Fig 1. - The very common Japanese ball bearing key sold under many names.Fig 2. - The Japanese ball bearing key gets its name from the ball bearing trunnions shown in the photo.
Fig 3. - Note the key also has a distinctive cone shaped knob on the shorting lever.
Fig 4. - The key commonly uses this less expensive insulating material to insulate the binding posts from the frame.
Fig 5. - Most of these keys have the word "Japan" stamped into the bottom of the key base.
