Coleman Quickbed with Built-In CPX 4D Battery Pump, Queen Interchangeable battery system -- CPX power source can be used with other Coleman CPX products Use 4D batteries (sold separately) or upgrade to rechargeable CPX power source Soft sueded top for luxurious comfort Airtight System with Double Lock Valve so your mattress stays inflated Higher-grade PVC for reliable puncture-resistance Location, temperature, and humidity will affect the firmness of the airbed. Airbeds will need to be occasionally re-inflated (topped off) to maintain desired firmness upon initial use and when used for more than a few days as material tends to relax over time.