Your question was: Why doesn't the air pump nozzle fit in my ball?
Our experts said: Adapters for standard air compressors you would find at a service station are included in the package. The hole in the Exercise Ball may be a tight fit due to the manufacturing process. It should loosen after the first inflation. If you are unable to insert the nozzle with moderate force, contact customer service at 1-800-321-2135.