I know in the instructions it says to set out for 48 hours to inflate, however when I first opened I was so skeptical as to how it would be able to expand because it was SO uneven! However I set it out anyway, once I checked back in a couple hours it had fully expanded and looked perfect! It made our bed feel like an entirely new mattress, both me an my boyfriends body and back aches are long gone. Even our dog never wants to sleep on her dog bed anymore which she used to love! So easy to fall asleep now and we wake up well rested. Every since we got this we’ve been sleeping through the night no problem. And you can’t beat the price considering Serta has basically the same thing but for 260. Definitely recommend!