This marine chiller is subject to ambient room temperature and other additional heat sources in the aquarium, such as lighting, filters, pumps, power heads and even pumps that are integrated into equipment, like protein skimmers and various types of reactors. These coolers are designed for tropical marine and freshwater aquarium systems. You will need a larger cooler than stated for native marines and specialised lower temperature freshwater set-ups. It uses the environmentally friendly refrigerant R134 A and has a pleasing, contemporary design.Features Over-current and overheat auto-protection system.Utilizes high-quality material.Suitable for use in both salt and freshwater.Built-in temperature memory.