Does anyone know what a magslip motor is?

I have a load of these NOS and a few others – Anyone know what these are used for? They are all jet age and probably come from hunters, canberras and lightnings. I’m trying to find them a good home as they are good servicible components.

Magslip motor – no date
Magslip trans – no date
Synchro resolver (dated 1966)
Reversing motor generator – undated

I have some pics if anyone is interested.

Thanks

Elliott