Sturdy Steel Frame With Poly Jacquard Cover AS SIMPLE AS UNFOLD & UNWIND - Requiring no tools and zero tedious assembly, the innovative No Assembly box spring requires only unfolding to become bedtime ready; the hardest part will be taking it out of the box DURABLY ENGINEERED - Durable steel is used to construct the interior framework of this reliable foundation; twin and twin xl size supports a maximum weight capacity of 350 lbs, while all other sizes can support up to 700 lbs LOW PROFILE DESIGN - A 4 inch height is perfect for taller mattresses or for those who enjoy their bed lower to the floor THOUGHTFULLY PACKAGED - All parts and instructions are packed into one compact box that ships straight to your door Worry-free 5 year limited warranty included; box spring only, a bed frame or platform bed is required to support this foundation and is sold separately