Your fish will stay happy and healthy in waters warmed with Aqueon Pro Heaters Submersible Aquarium Heaters. The Aqueon Pro aquarium water heater is an accurate and easy-to-set solution for your tank-heating needs. Simply calibrate the fish tank water heater (ranges from 68-88°F) and submerge. The electronic thermostat returns precise accurate temperature readings within +/-1°F. You can easily adjust the heater's setting with the calibration dial and easy-to-read temperature scale. You will easily be able to tell whether or not your aquarium water heater is active with the color-coded indicator light. Aqueon Pro Heaters Submersible Aquarium Heaters feature a two-setting indicator: red light means your tank is being heated, and green light means it has reached your desired temperature. The Aqueon Pro fish tank water heater combines both convenience with functionality. The fully submersible design lets you place it in your aquarium either vertically or horizontally to accommodate your unique setup. Use the included suction cups to secure the aquarium water heater to your tank wall once you are happy with its placement. The long-lasting, precision performance of the Aqueon Pro is attributed to a combination of features including the shatterproof and nearly indestructible aluminum core. Aqueon Pro Heaters Submersible Aquarium Heaters feature no glass components and are covered entirely in thermal plastic to protect against damage and wear from extended use. The Aqueon Pro fish tank water heater is available in a variety of wattages to suit different tank sizes. Be sure to find the one that is designed for your tank. These heaters are ideal for both freshwater and saltwater aquarium setups.