Instruct: Classify the given review into positive or negative sentiment.
Query: Not impressed.. Sent back after one night. Defective

I purchased this item after reading about an hour of reviews. I was excited to use the product on a upcoming camping trip. When the item arrived I inflated the bed according the the instruction book and immediately noticed that the outer chambers inflated approx 4" higher then the inner camber. This caused a V shape to the bed. I tried even letting some air out of the outer chamber and adding more to the inner but if you laid to close to the edge you would fall out then. I figured I would try if for the night, that was a mistake. when I woke up about 7 hours later, the bed lost about 2" of air and had a back ache from hell. I packed the bed up and had UPS pick up the package 6 hour later. That's my experience. I reorder a different mattress from a different manufacture, have my fingers crossed.