In radio shacks case, I think they may mean 12 actual volts, being as
their
bulbs usually don't last very long when used with a 13-14 v supply...

Add a resister to lower the voltage, if you want it to last
longer...better yet..
convert to white LEDs...My 706 has those things...Maybe changing those
dang bulbs
will become a thing of the past...MK