Thanks to its 11 flexible cleaning fins, the Hobby Alg-Devil cleans the very same spot several times in just one move. Even persistent algae have no chance. Simply screwing off the handle allows for a total disassembly for cleaning purposes. The flexible fins rule out scratching of the panes or damage to the silicone bonding. The Hobby Alg-Devil consists completely of water-neutral plastic material and can therefore also be used in marine water aquariums without any problems. Just a clear view everywhere!Hobby Alg-Devil+ plural cleaning in just one move due to 11 flexible cleaning fins+ no scratching of glass pane+ no damaging of silicone joints+ for fresh and sea water aquariums alike+ easy to use+ replacement fins separately available