The Serta Raised Air Bed Mattress with Never Flat Pump technology makes getting into and out of bed easier and just might be the most comfortable air bed you’ve ever slept on. Able to maintain it’s pressure throughout the night, Never Flat™ eliminates sagging and loss of air pressure that is so common in airbeds. Never Flat™ technology is an auto-engaging, whisper quiet pump that maintains constant air pressure throughout the night for an undisturbed, continuous night’s rest that is never flat. Choose your desired comfort level–Plush, Medium, or Firm–and let the powerful Primary Pump inflate the bed. Once inflated, the Secondary Pump continuously monitors and senses when it needs to silently engage in order to maintain the chosen comfort level throughout the night.