The Motorola CB radios were most popular in police and other public safety patrol cars in the mid 1970's and early 1980's. In fact in some states, they are still in service in Highway Patrol and State Police cruisers. The Motorola CB base stations in Highway Patrol District Headquarters, and State Police Precincts are a thing of the past for the most part. To this day, on rural highways, and lonely sections of interstate, you may even come across an officer on a Motorola CB.
Motorola model 4002
This model is AM only, with PA and LOCAL buttons. It has an illuminated channel dial, and RED channel 9 indicator on the channel selector. Unlike later models (4022, and others) there is no LED channel indicator. The signal / transmission meter was pretty much the same on all mobile and base radios. The notable exceptions possibly the 550 series radios.
Motorola model 4022
This model is AM only, with PA, LOCAL and EXTEND buttons. It has an non-illuminated channel dial, and a LED channel indicator. The signal / transmission meter is the standard one on most of all mobile and base radios.