Antique Emergency Exit light made by Internalite of London. 
The glass sign hangs from a metal case and the whole thing is suspended by chains. The chains can be removed if required and it could be hung straight onto the wall, via holes on the reverse of the casing. 
At some point in its life it has suffered a small amount of damage to the top right corner of the glass, however this is not immediately noticeable and certainly doesn’t detract from the sign. 
It has been rewired using twisted fabric flex and LED lighting, so will not get hot, nor use a lot of electricity. It has been PAT tested and is ready for use. 
Measurements: 28 x 5 x 20cm high