Mentor-Meyer Super-Speed reflex camera
A. O. Roth, London; 4½ x 6cm., the shutter winding knob marked PAT NO. 190302/21, a Meyer Plasmat f/1.5 3½ inch lens no. 432844, maker's plate MENTOR-MEYER. A. O. ROTH. PHOTO MANUFACTURERS. 85 RINGSTEAD ROAD, CATFORD, LONDON SE6 and single metal slides
Literature
Channing & Dunn (1996), British Camera Makers, p. 109.