They are like new in the original foam padded Ampex shipping
believe these were all used on the Ampex FR1200, Ampex FR3030, and
Ampex TM2 data
recorders, but they might be compatible with other types of machines, such as Thorn EMI, etc..
This is up to the buyer to determine.
Ampex data recorder record/reproduce heads in better condition
not be found anywhere.