Single-chamber filter system for effective pond water filtrationThe single-chamber filter system contains filter media for cleaning the pond water. The water flows through filter foam and a Filtra sub-net in the box.Features:Compact box filter for ponds Filter foam removes coarse dirt particles Filtra-Sub for optimum biological filtration Available sets:Box Filter 4000 | up to 4000 liters of water with fine and coarse filter foam + Filtra-SubBox Filter Set 4000 | up to 4000 liters of water with fine and coarse filter foam + Filtra-Sub + pump 1000 l/h + hoseBox Filter 7000 | up to 7000 liters of water with fine and coarse filter foam + Filtra-SubBox Filter Set 7000 | up to 7000 liters of water with fine and coarse filter foam + Filtra-Sub + 2000 l/h pump + hose