Help to ID an old mic

[Ruskiko]

I was given an old Realistic mic labeled CARDIOID " CONDENSER MICROPHONE".It came in a box with the manual for a realistic 33-1080, but doesn't appear to be the same microphone. I was hoping to ID it so I could find the specs.
thanks

 

[cannabis]

does the top unscrew

so a battery can be changed?

if so, it's probably one of their

electret mics put out

about 30-40 years ago

with specs similar to this:

http://support.radioshack.com/support_audio/doc65/65746.pdf