Horseman 6x12 Back - Machined for larger frame (only one)

This is a used but fully functioning Horseman 6x12 back, for use with the Stereo 12, Stereo M, and most large format cameras.  It accepts 120 film only.

This back has been machined and modified by Mercury Works to shoot a 117mm wide frame (enlarged from the original 113mm).  This enables wider stereo slides (48mm or 50mm, as opposed to 45mm) when shot with a Mercury Stereo camera.