Finnex Digital Aquarium Controller HC-820W Series Finnex Power Supply you know the THD is

you know the THD is built to outperform standard glass heaters

Safety First: High-Temp Heater Guards

The 24/7 feature starts with a cool lit Dawn

Easily adjustable high/ low-temperature settings with an audio alert separates this aquarium heater controller from the rest of the competition

Built‑in dual circuit safety provides an added layer of protection by monitoring system performance and helping safeguard your livestock from dangerous temperature conditions

Finnex Digital Aquarium Controller HC-820W Series Finnex Power Supply you know the THD isThe HC 820W controller uses an advanced digital processor that monitors and controls the water temperature in your aquarium. The heating controller receives temperature data from the remote sensor in the aquarium. The remote sensor contains no bi metallic contacts to arc, corrode or wear out. This allows the HC 820W to have precise control, keeping the water temperature stable while avoiding wide temperature swings common with low quality aquarium