Although unnamed this appears to be an overseas model of an early Duplex Ruby. The camera has the familiar T-P corner bindings to the hood, the speed dial though is painted black and mounted on a wooden panel, illustrations show a brass panel. There is no plaque containing patent information. The shutter is the improved Unit model of 1912 which is fitted with T-P's Auto Exposure Stop, this replaced the separate setting of the tension and slit width.

The Unit shutter

is based on the patents of F. P. Whitehead and W. F. Giles (BP 15548/08 and 28174/06). The earlier patent was probably superseded by the 1908 patent. Early examples of the shutter which was sold by T-P from about 1910 had a tension selector cog on the left-hand side and slit-width selector set on a dial on the right-hand side (when using the camera). The combination of tension and slit was found on an attached table which gave the speed. From 1912 the tension setting was no longer required and the speed was set directly on the dial. The shutter was widely used by other manufacturers including Houghtons.

The Unit was replaced by the Ruby shutter on T-P cameras from 1913.