Double Ended Brush 1m The Aqua One Filter Brushes come in two different styles. The Double Ended Brush is perfect for keeping your pipework clean, and provides you with two large fluffy brush heads on 1m of flexible pipe, so you can push this through your existing filter pipes to ensure a full clean inside, getting rid of any algae and slime that may have built up inside, so your water is always flowing clean. The Aquarium Brush Set comes with three different sizes of brush head, each on a length of wire to hold onto. These are perfect for cleaning all within your filter, getting into all the air flow holes and removing any debris, dirt and algae that builds up around the filter, so it can operate as efficiently as possible. Keeping your filter clean is essential in ensuring it can run properly and keep your aquarium clean. The most common cause of a filter failing is dirt and debris building up, especially around the impeller which then causes it to clog up and stop spinning, so ensuring this is removed proerply can keep your filter running for much longer!