The Siemens and General Electric Railway Signal Co was formed in 1926 and produced a huge range of railway safety signalling systems. This super rare survivor was produced around 1926-28 and was in in direct competion with W.R.Sykes and R.E.Thompson . Thompson produced a similar art-deco style instrument of which many have survived, this design has a handful of example which have survived. Produced to a very hig standard with a bevel ground glass too. In excellent condition.