Would love to know what this is?

[Knobhead]

Thanks bomjac, I never thought 1/3rd of a RMU. I’ve only ever come across 5 of them as against 100’s of OCB / VCB’s. 3 of them were that old they were DMO and could only be operated “dead”.

 

[thepurple1]

I saw something like this, that was ripped out when they fitted new lifts into building