Allows you to provide filtration for a pond without the need for main electricity. Whilst there is no UVC unit, the filter comes with plenty of foam and biomedia (sold separate) to provide a good level of mechanical and biological filtration. Working in a very similar way to an All-in-One pond filter, the pump fits inside the box and the whole box is submerged. IMPORTANT: Not designed to keep ponds with koi or heavy stock of fish clean. PLEASE NOTE THIS FILTER DOES NOT HAVE A UVC