A fine example of a lamp in/out indicator produced for the G.W.R. by R.E.Thompson at this first works at Teddington. This instrument was produced from the 1940s-45 and in in excellent ex box condition, the case has the original un-engraved brass plate which was supplied by Thompson. Probably when in use a plate was affixed on the block shelf. This instrument has been tested and all coils are in working order.