Pacific Coast Imports chiller/heater combination units are top of the line, and are specifically designed to keep your aquarium at a constant temperature of your choosing. These units are by far one of their finest products, and to be honest there is nothing else like them on the market. These units are made with high grade titanium heat exchangers, and are digitally controlled for precise measurements of temperature with only a +/- 2 swing. Each unit also comes with its own 1 year guarantee. We offer only the very best at the lowest price.