component ID

I am cleaning out some of my misalliances electronic bins and I have a handful of these components. Not sure what to call them or what the "metal/ceramic" disk is made of. Disk and contacts are non-magnetic.

Guessing its a kind of signal delay or resistor. Anyone know?

PS. Happy Fathers day to all the dads.

Any markings?

That's a PTC (Positive temperature coefficient) resistor.

I have seen them in CRT TVs as part of the Degaussing cable setup, and fridge compressors as part of the 'startup coil' used when the compressor as starting.

https://en.m.wikipedia.org/wiki/Thermistor

Quote. {PTC (Positive temperature coefficient)
Most PTC thermistors are made from doped polycrystalline ceramic (containing barium titanate (BaTiO3) and other compounds) which have the property that their resistance rises suddenly at a certain critical temperature. Barium titanate is ferroelectric and its dielectric constant varies with temperature.}

There's Silver on their contact faces, but a tiny amount of it. I don't bother saving them up anymore as I don't think there's anywhere they could be sold.