[Closed] Thermal paste.

For installing a CPU? Arctic Silver.

Try asking your local supplier of solar water heating systems; they use it for the junction where the copper end bulb on the collector plugs into the blind hole in the manifold and once you've installed the collectors there is most of a tube left over.

The collector bulbs get very hot indeed; I burned my hand on one I was handling on a dull day inside a conservatory.

Thanks for that.
Yes, for CPUs.

I see they come in a syringe.
Does it go off once opened if the lid is kept on?

No worries, it will keep for years.

Excellent, thanks for the info.

If it's Beryllium oxide based try not to get it on your hands.