these lifts are very sturdy. the shape resembles a road cone, and they are pretty wide at the base. we have a king size bed with no bed frame. i ordered 2 sets of these lifts, total of 8. the 8 lifts alone holds the whole box springs and mattress securely off the floor. i put one in each corner, and 1 in the middle of all 4 sides of the box springs. the weight of the bed holds itself pretty square on top of them. the only thing to watch for is when making the bed. sliding it around while putting the sheets on, sometimes gets the lifts out of place, but only a tiny bit. we just wiggle them back into place after the bed is made.
Rating: [5 of 5 Stars!]