All I can say is the r&r development team at Top Fin blew it on this one.

The largest sized Top Fin algea magnet to be specific.
1- It removes algea just fine.
2- It has a big handle to help you maniplulate them well.
3- The inside magnet has a low profile so you can get into the tight spots.

What they totaly blew it on is the stupid thing doesn't float. If you move to quick and lose magnetic contact your swimming to get the stupid magnet off the bottom. For small tanks this would not be that big of a deal. BUT THIS MAGNET IS SUPOSED TO BE FOR LARGE TANKS. All they needed to do is put a small air pocket into it so it floats.
Knuckle heads......

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.

Mine are quite small, so I have three for my 90 gallon tank

I use the "Mag-Float" algae scraper. It floats but has not have a handle to control it. They come in many sizes, this biggest one being for 350 gallon aquariums. This didn't really matter to me when I bought mine. I figured bigger was better and that since the 350 one was the biggest it would make the quickest work of all my aquariums. Wrong, that thing is extremely powerful. I had trouble moving it one my smaller aqauriums, 55gal 37gal and 29 gal, because their glass is so thin. Eventually the felt on the outside piece started coming off, exposing the hard plastic on the controller side. The rough edges were enough to leave minute scratchs in the outside of my aquarium glass.

The algae cleaner i have is the mag float one. I dont have to use it much as i have a plec. However it only gets rid of normal algea. Ever so often i get this tuff stuff that i can only get of easy with a razor blade so i am interested in these magnets that have blades. What are they like and the name is Top fin right??? What do they cost? I am in UK