Using a 127 film, it would make sixteen 30 x 40mm images per roll with focal pane shutter speeds of 1/25 to an unusually high 1/500 + B and a timer.
To accommodate ortho or pan film, there two red and two green oval windows on the rear selected by sliding the flat panel inside the rear.
There is a tripod mount on the base and a cable release connector on he front. panel.
This example is fitted with the swing-up Type III (square) telescopic viewfinder, (although the view is circular).
Also included is an old; Genuine Cowhide case. The zip is jammed and the stitching on on side is undone.
This camera is in very good condition for its age. As can be seen in the photo there is some corrosion on the rear of the front panel.
The cloth shutter and bellows look fine with no pin holes. The lens is bright and clear. The iris responds.
The shutter speed does sounds as though it varies according to the speed setting and the timer works.
Apparently, it is very rare to find a Derby in such good mechanical condition.
Dimensions: 11.5 x 7.2 x 3.3cm. Weight:768gm.