Betta choice UV aquarium filters are a range of external power filter. The filters are easy and simple to use, featuring a high output pump, built-in Ultra-Violet Sterilizer, and an easy-to-clean multi-stage canister filter. UV sterilizers slowly pass aquarium water pass an ultraviolet (UV) bulb, which irradiates microorganisms like bacteria, algae, and protozoa. By damaging their DNA, it can shorten their life cycle and limit population growth. Built in optional surface skimmer and easy priming system. Suitable for coldwater, tropical, marine and even turtle habitats. 700 UV For aquariums up to 150 litres, 700 litres per hour, max head height 0.9m, running power 9.5w, UV 7w, canister volume 5.8l, pipework size 12mm. 1050 UV For aquariums up to 230 litres, 1050 litres per hour, max head height 1.4m, running power 15w, UV 7w, canister volume 8.5l, pipework size 16mm. 1620 UV For aquariums up to 360 litres, 1620 litres per hour, max head height 2.0m, running power 33w, UV 9w, canister volume 12.5l, pipework size 19mm. 2000 UV For aquariums up to 540 litres, 2000 litres per hour, max head height 2.4m, running power 43w, UV 13w, canister volume 20l, pipework size 20mm.