This is a copying camera consisting of a bed with a central lens standard and interchangeable standards of various formats for the original (what is to be copied) and copy.

This example has 10" x 8" standards for the original negative and the copy negative. With reducing frames this would allow copies to be made from various size originals, enlargements of the centre portion and reduction onto smaller negatives.

A second 'original' standard is present to which a sliding back for stereo negatives can be attached. The back can slide vertically in the standard to position a particular part of the original. A holder for stereo negatives is contained in the back and able to slide horizontally, adjustment screws are present to fix the movement.

A second 'copy' standard has a removable sliding back. This carries a focusing screen. A negative holder for stereo images would have been fitted but is now missing. This allowed stereo negatives to be copied/transposed or portions of the original to be enlarged. Lantern slides could also be produced.

In the F.J. Cox catalogue of 1873 a similar camera is described as "for reducing or enlarging negatives or for producing transparencies on ground glass or opal glass". The description is of a camera with bellows though the accompanying woodcut shows an earlier sliding box arrangement.