As pictured, an EG&G Princeton Applied Research model 5101 lock in amplifier.

Has been kept in a workplace store room for a number of years, but no longer required.

Case, buttons etc are in good condition. I've powered it up and it powers on, as can be seen in the video. However I have no way of testing it beyond that. You're welcome to test it when collecting, location is Huyton, outskirts of Liverpool, between J5 and J6 of M62.