Designed for use in SeaClear System II Aquariums supporting a saltwater environment. SeaClear's Protein Skimmer for saltwater environments improves water quality, increases oxygen content and removes unwanted waste products that accumulate and pollute the aquarium water. The Protein Skimmer is housed internally in a chamber next to the pre-filter chamber. Must be attached to an air pump (not included) to function properly.This product ships by UPS ground only. We are unable to deliver to P.O. boxes, APO/FPO addresses, Alaska/Hawaii or Canada.