This is the centre and main part of the watch’s case. It houses all the working components of the movement as well as the dial and hands. The lugs, to which the strap or bracelet is attached is also part of the case middle.
As with the case back, case middles are most commonly manufactured from stainless steel but may also be machined from gold or other precious metals. The bezel with its settings and the case back complete the case middle.