I absolutely love the look of these but after having them up for the last 3 months I need to take them down because they are so heavy that the knobs do not keep the lamp lift and they are not adjustable. Not only can you not adjust them and they are now resting on my bedside tables, the light glares because of the glass and the glass gets really hot!  I do not recommend these do to these reasons.  All modern is a 5 star company as they are crediting me back!