Introduced in December 1959 (ref. Tabs 17/3)
Replaced Patt.43 in 1960
Designed by Morgan McLeod.
A modification was made for the German market, by Strand Germany, consisting of a colour frame cassette which could be fitted to the front of the lantern. This enabled the use of coloured glass as well as frames with standard filters (see photo from 1972, below)