Swing-Out

This new arrival is an 18 size Elgin pocketwatch is a classic "swing-out", open-face case.

The movement is held in a ring which is hinged to the one-piece back. The front bezel is threaded. At one time, swing-out cases were required by railroads since they have that one-piece back to provide better dust protection.

Way back, before the meaning of the phrase changed, these watch cases were also called "basket cases".