[Heathkit] Heathkit IM-17 battery?

[Mike McCarthy, W1NR]

I have a Heathkit IM-17 "Utility Voltmeter" and need to know what type
of 8.4V battery is used.  I have found an Eveready #206 that is 9V that
looks like it will fit.  Can anyone tell me what type battery you are
using?

Thanks,
Mike, W1NR