The first model Koilos appeared in 1904 with a friction brake. The casing was bright aluminium with 'worm' lines, on the right was a pneumatic release cylinder. On the left a finger release and a button which opened the shutter for focusing. The speeds were set on a dial at the top of the shutter.

Around 1906 the friction brake was replaced by an air-brake, at first on the smaller sizes and later on the larger models. The appearance also changed - the pneumatic release was placed inside the case and a cable release socket was added. The delay cylinder was placed horizontally along the top and the focusing button removed.

At a later date the bright aluminium finish was replaced by a black paint finish. Small engraving differences (i.e. the anchor symbol) exist.

The image, right, shows a friction brake model.