I pickep up a couple of these from Aldi for $15 each.
They have enough clamping force to dammage your ceiling
, but they are no where near comparable to the Manfrotto autopoles. The top extension is very thin and they have ball heads at each end which would go a long way to helping them flex and collapse if you nudged them hard enough in the centre. No way I'd be hanging a monolight of them as shown above. For a small fabric backdrop or to hang a diffusion fabric etc they are great.
I wouldn't put anything on them you wouldn't like on your head 

