Here the actual ACARS radios in use at the Toronto Pearson International Airport CYYZ.

My friend at Nav Canada took them after doing some repairs. Thanks to him for this inside look at the CYYZ radios!

The box at the bottom of the rack is the ACARS controller that interfaces between the five radios and ARINC, and
passes on data information to and from the aircraft. The transmitters are sitting above the controller.
If you're interested at the frequencies they are,

129.125 MHz
130.025 MHz
131.475 MHz
131.550 MHz
136.850 MHz
136.975 MHz