Ideal for removing coralline algae and calcified deposits in glass aquariums","Rubberized handles and blade attachments made from strong abs plastic and stainless steel that will not rust.","Plastic blade gently scrapes off most naturally-occurring algae without scratching the glass or acrylic surface.","Steel blades work on hard coralline algae and calcified deposits.","Metal and plastic blades are interchangeable and replaceable.","Extendable handle length is easy to adjust with a simple twist.