A CB radio system type Albrecht AE 7500 is installed inside the driver´s cabin. The roof-mounted antenna is a Sirtel Gamma 1R. The CB radio can be set to European standards and also to North American frequencies / channels. It is very large compared to my old Walker President, but unfortunately the old CB radio was stolen from my Land Rover Defender.
Operation requires 12V, so that it a small 24V -> 12V converter was installed in the cab. The switch for the converter is on the dashboard.
We use two Albrecht AE 2990 AFS handheld radios to communicate outside the vehicle or when directing the truck in tight spots. The hand-held radios can be operated with normal AA batteries, so no additional cables / chargers are needed.