Twin Bed Frame with Trundle and Headboard.
Once you realize the flexibility they offer you suddenly decide that you cannot live without it. Obviously, the frame is metal and weighs a little, but that's no reason to make them awkward and squeeze it and let go of a finger! Before you buy a pop-up trundle frame you check many reviews and make sure that people are happy with the mechanism used. When your trundle bed is not in use, the popup will be lowered and the mattress and the now digitized frame will fit under your standard bed.