The pay phone is a different type made out of metal which is surrounded by a layer of another metal. It includes an attached phone with a rotary dial, a coin slot to insert the coins, and a clam at the top.
When SpongeBob is cleaning windows at the Krusty Krab he sees Plankton using a wrecking ball. SpongeBob thinks Plankton is going to hit the Krusty Krab, and then goes to the pay phone, (which is inside of the Krusty Krab) to call Mr. Krabs, and tells him about it. A voice recording from Mr. Krabs is heard which tells him "Please deposit 25 cents to continue this call." SpongeBob puts in twenty five cents and warns Mr. Krabs about Plankton.
SpongeBob finds a pay phone and calls Squidward and asks what he should do. The phone operator says that he needs to put in one dime to continue his call with Squidward. He spots an abandoned sofa and then sees three fish sitting on the sofa. SpongeBob puts his hand in the sofa and finds two nickels instead of one dime. He isn't able to continue his call, as a petty cab driver, Scott, drives him to a restaurant.