One-shot tri-colour camera made by W Watson & Sons Ltd. Aaron Hamburger design. Serial No. 14626. Back and side plates. For 1/1 plates; transparent reflector (missing) splits beam in two paths - straight through onto bi-pack of two plates at back, in special holder with rubber covered pressure plate; reflected beam onto single plate at side; fitted with Ross Rapid Symmetrical lens No 22403 (not original). Rack focusing, with linkage swinging back holder to allow for toeing in at different distances.