I broke it while trying to repair a nearby component on a 1970s board. It has two wires at one end that look like they are going to a coil and two axial wires. One of the axial wires came out with some pieces of glass.
The only markings are "P/F" which mostly likely means Philco/Ford.
The "silkscreen" was marked with "S1" and nothing else.
The end with the two coil wires is angled at 45 degrees I presume to indicate polarity.
I also need a way of working out what value it is so I can get a modern replacement.
Best Answer
It's the outer magnetic coil of a reed relay. The two axial connections connected into the glass body are for the reed contact: -
The picture above shows the coil (bottom) and a couple of reed contact options with the top being a SPNO. The lower one looks like a 4PNO device But they could easily be NC types.
Here's an article that shows this explanatory picture: -
Good luck.