ALITA® Linear Air Pumps are engineered for long life, continuous and intermittent operation. Like tires of a car things wear out and need replacing. The good news is if your air pump runs but does not produce enough pressure then most likely its time to replace the diaghrams. These kits also include the nuts, washers and replacement air pad filter. Yes it has an air pad filter! When is the last time you cleaned your airpump air filter? Not to worry if you purchase from our store we will kindly send you a reminder every few years to keep things in working order and your wet pets happy!