Bellows Pumps: The simplest and most traditional mechanism. It looks like a small plastic “accordion,” which you press down manually to push the water into the bowl.
Piston Pumps: The mechanism works like a small manual pump. You pull the piston (handle) up and push it down to send the water forcefully into the bowl.
Electric Pumps: It operates with standard batteries placed in a special waterproof compartment. All you have to do is press a button.
