EncapSulite "Copycolor" 10W SOX Safelight

Here is something I never thought I would ever be able to find, a very rare 10W SOX Sodium darkroom safelight. Strangely it is rated for 220V rather than 240V so I am running it from the Variac as our supply here is rather high at 245V. I have seen others like this badged Agfa-Gevaert, so I don't know who actually made them, this one is labelled "EncapSulite International Ltd.", which is a name I have not heard of before.

Only GEC ever made the lamps commercially; I believe Philips and Thorn produced experimental/prototype lamps but they were never marketed. They were used for security lighting and for this darkroom safelight, but were never particularly successful and were sadly made obsolete around 1990.

Before anyone mentions it, yes there should be a gel filter behind the front plastic cover over the lamp, but there wasn't one there when we bought the fitting, and in any case, it's all the better to see the lamp with..!