As other reviews say- the top piece does not attach, it merely sets on the other. End cap shelf on "desk" part provides more sturdy desk when it has weight BUT you must remove all weight from shelf when moving/altering the desk as these "wood" pieces will tear and come out otherwise. This is wood pulp packed to make boards type of composite piece, not solid pieces of wood construction. Fair piece for the price. Not as movable/changeable as I had hoped. Also must have desk set fully expanded from shelf (no matter the angle) as uncentered it messes with the weight and makes an unsteady desktop due to weight distribution of flimsy particle board.