Bioscape Small Aquarium Magnet 

Product Name: Cleaning Magnet
Easy Removal of Algae from Aquarium Glass
Will not scratch Aquarium Glass
For Glass Aquariums only
Ideal for Aquariums up to 8mm thick glass

The Bioscape Algae Magnet enables you to clean the inside of the aquarium glass without getting your hands wet.
The powerful magnets ensure a tight grip and the non-abrasive cleaning pads will not scratch the glass surface. The Algae Magnet is suitable for fresh or saltwater aquariums.