Has instructions that are easy to follow. Comes with an allen wrench, but pliers help to tighten the wing nuts. Has wingnut and screw sets for all of the legs and attaching pieces so be prepared to do this. Not hard, just time consuming, but sure beats having to put in those wooden slats like the basic ones without the center support that this frame has, or worry about the slats falling through. I suppose you could add some flat slats or strong twine for added support.
Just be sure the legs are tightened as they bend open and close for storage and might bend if not properly tightened.
Use the smaller screws for the headboard attachment piece with screw facing outwards of course, and the larger screws for legs and frame support.
One size fits most; twin, full, queen.
I am very happy with it so far...no issues for the last few weeks : )