I suppose you get what you pay for... I cringed when I had to pay over $100 for a magnet cleaner. Yes, this has stronger magnets than cheapo magnet cleaners.But then again, I have spent some money previously for magnets that didn't work well. Some have said that it's good for 3/4" glass, but it always came popping off when I started cleaning my aquariumNOT this one. This is a STRONG magnet. This one won't "pop off" (the inside part). But if it does (and probably only when I transfer from one corner to another, but then again, not likely on my 3/4" glass), the inside part will FLOAT.I cringed when I paid over $100 for this. But I smile every time I use it. I have all but forgotten that initial shock, and have decided that the price is worth it. Still... it it were any less expensive, then I would happily give 5-stars for this. So my ticking off one star may be a bit unfair, but I'm the reviewer, and the $100 still hurt. ($100 for a magnet hurts; $1,000 for a really good skimmer didn't -- so it's not that I'm being stingy; that's just how I feel, and my review is a reflection of that).