Twin Size Air Dream Sleeper Sofa Replacement Mattress Finally, the comfort of a premium mattress is available for sofa sleepers. The 11-inch thick, air-over-coil design is so comfortable, your loved ones will forget they're sleeping on a sofa bed. Plus, because this mattress is designed with high-quality, hypoallergenic materials, even the most sensitive guests will get a good night's sleep. The Air Dream mattress has a Three-Year Ltd. Manufacturer's Warranty on the mattress, air bladder, and air bladder valve. There is a One-Year Ltd. Warranty on the motor.