Edgar 4 Inch Low Profile Wood Box Spring/Mattress Foundation, King

I bought the Twin size and there is no center support whatsoever, only edging. And the included slats are thin n useless. I had to modify by adding thick wood in the entire center— otherwise it’d ruin my matttress.

Hello, The slats are 3" inches apart. Yes, the slats have a center support.

Yes, Two twin box springs can be used with your existing frame.

You must have a single frame. Maybe it can be expanded to accommodate a full size (54X75).

Two twin box springs will measure out to be 76''W x 74''L; therefore, they will be too short in length for a king size bed frame.

We do not recommend using a Twin bed frame for a Twin XL Mattress, due to the mattress dimensions hanging over the bed frame. This could cause damage to the mattress.

No metal, wood. You would have to purchase a frame to set it in otherwise it will be on the floor. Does not come with the frame.

It's quite easy to do. You hook the long sides and the shorter top and bottom sides together with the provided hardware. The slates are already secured together with fabric straps so you just roll the slates out on the newly assembled frame. I like that the slates are provided (for a QN) in two sets rather than a large single roll that would have been difficult to manage. The hardest part is getting the cover on over the fondation once complete, but it's worth the effort because it fits snuggly and looks sharp.

I don't recall the specific sizes, but it was easy to get up a flight of steps by myself. I was unable to fit a full size box spring up my stairs but in packaged state it worked just fine. I hope this helps!

The distance between wooden slats is approximately 3".