For years the name Visi-Therm has been the industry standard for excellence in aquarium heater performance and reliability. Now there is the Visi-Therm Deluxe – an advanced-design submersible aquarium heater that constitutes the next important step in aquarium heating technology. Water-calibrated to ensure precise temperature selection and superior performance the Visi-Therm Deluxe delivers the ultimate in direct-set control compact double-sealed durability...and certified accuracy to within one degree. With a simple click of the dial you choose the ideal water temperature. The custom Double-Suction Mounting Bracket features an adjustable three-position window that ensures easy-to-view temperature setting. And of course every Visi-Therm Deluxe is CSA listed... designed to exacting standards for extended submersion and operational safety.