When I received the item was a bit sceptical about whether it would work. Anyway, tried it on my carpet tiles and did not work at all, but used it on my stair carpet and it work excellently - really scrapped up the dog hairs!!
Can for see a problem, the metal frame sits into a wooden handle - even though I've only used it a couple of times - the metal frame is moving within the handle area (hope this description makes sense), but the actual comb really does what it supposed to.