With my new 1/2" thick glass tank, my old MagFloat 350 just wasn't up to the job. So, I ordered an Algae Free brand Hammerhead model. I am impressed... magnets are STRONG, and it cleans well. The velcro on the inside half is flush with the edge of the unit, so it gets right up to the silicone inside the tank.
The velcro and felt are easily replaceable too.