I have got one just like that, it has got these vicious blades on it. The bloody thing will take your finger off if you're not careful, it is so incredibly strong, and needs to be to remove the toughest of algae which it does.. This one doesn't float either, I think the problem is, it's so full of magnet, it will never float unless they put plenty of buoyancy on it which would make it huge. Mind you, they wouldn't hurt if it was quite big. I know what you mean though, my new tank is so high, you'd literally have to get inside the tank to retrieve it.