The Patent Etui is noted for the very slim outline of the camera when folded. It achieved this by the folding arrangement of the front standard and by shaping the bed of the camera to accommodate the lens/shutter when closed. It was not distributed in Britain until 1928.

The Etui was made in two sizes: 6.5 x 9 cm, and 9 x 12 cm. Three models were produced: single extension, double extension and a Junior model (c. 1930) which had front-cell focusing. De-luxe versions finished in coloured leather were produced.

There are a number variances:

• With or without a spirit level on the brilliant finder.
• Some models have a rising front operated by a thumb screw and worm gear, others slide.
• The 'KW' logo on the front panel is not always present.
• The rear sight varies in shape.
• Cross front is sometimes present.

A number of lenses and shutters were fitted.