The patent pending Klir Drop-In Automatic Fleece Filter Di-7 V2 fits directly into most four-inch filter sock chambers that automatically unroll new material as it gets clogged, removing suspended particles from an aquarium and producing crystal clear water. The easy-to-mount, magnetic water sensor detects when the fleece is dirty and automatically advances a new clean section, offering months of maintenance-free filtration. The Klir Filter is a direct replacement for filter socks on sumps with sock trays. Simply remove the filter sock from the sump and insert the Klir. As water passes through the Klir filter and the filtering material becomes saturated with waste, the water level will begin to rise. When the water makes contact with the optical sensor, a motor is activated to advance clean filtering material. As clean material is exposed, water can then flow freely, lowering the water level in the sock tray and deactivating the motor. Includes V2 Smart Controller & Magnet-mount Sensor, and 50-Yard Roll of 50-Micron Fleece.