As example devices for CrMe communication, here are the globus parvus imaginationis and the globus magnus imaginationis.
The globus parvus imaginationis is a hollow metal ball the size of a large marble. It is enchanted with unlimited uses of the effect:
Share Imagination (CrMe base 4, R: Touch, D: Moment, T: Individual), which allows to transfer an imagination of the ball's user into the mind of another person.
To activate it, the user needs to say "Ita!" while holding the ball from below, and the recipient needs to touch the ball at the same time. [Enchantment level 15]
The globus magnus imaginationis is a hollow metal ball the size of a medicine ball. It is enchanted with unlimited uses of the effect:
Share Imagination With Many (CrMe base 4, R: Touch, D: Moment, T: Group), which allows to transfer an imagination of the ball's user into the mind of up to 10 other persons at once.
To activate it, the user needs to say "Ita!" while holding the ball from below, while each recipients needs to touch the ball - thereby identifying themselves as part of the T: Group. [Enchantment level 25]
Both items are simple Lesser Enchantments using common Arts, generally useful and not dangerous - so there might be many lab texts for them in circulation.
Some Jerbitons instead of balls use sculptures of fountains to enchant with the effects, calling such devices fons parva imaginationis and fons magna imaginationis.