It is a radio that is similar in shape to a walkie talkie. It is blackish gray in color and contains a built-in speaker on the upper side as well as an antenna on top. Below there is a red button used to either control the volume or switch the station and it possibly also serves as a power button. It runs on two AA batteries.
The radio is first seen when Mr. Krabs decides that he wants some music to play while he counts his money in his office. He turns on the radio to hear the station playing a catchy song called "Electric Zoo." Krabs becomes attached to said song and wants them to replay it once it finishes, though has trouble determining its music to the DJ. However, shortly after, they finally start playing it again, much to Mr. Krabs' appreciation.
After the song goes on for too long, Krabs' radio eventually loses energy and dies, to his misfortune. Since the batteries still have a fair amount of juice in them, he decides to give them to his daughter Pearl for Christmas.