Wooden box containing strobe for producing flashes. Box can be plugged into power supply. Wooden box with metal handle and plug socket on back. Behind door is large glass bulb in ceramic base surrounded by concave mirror.
The Vi-Tan unit cost £15 in 1939, the average wartime wage was c£6 - http://www.thescarboroughnews.co.uk/news/plugging-into-sunshine-in-1939-1-5910210.
