Uniclife HT-6050 Aquarium Heater Submersible with Thermometer for 10 Gallon Fish Tank, 50 W Wide Application: HT-6050 heater is suitable for most tropical freshwater and marine aquariums which volumes from 5 to 15 gallons. A heater is a fish tank set up necessity if you have tropical fish. Easy Adjustment: A visible temperature is displayed on the upper of heater, allowing you to precisely control the temperature. A rotary knob on top to adjust temperatures that range from 68F to 93F (20C - 34C). A good range for most fish is 76 to 80F (25- 27C). Fully Submersible: Water-tight sealing IP68 waterproof design, Strong suction cup clamps tightly fix the heater to the tank vertically. The Red indicator light on while working Explosion Proof: 2 mm extra thick Quartz Glass is shatterproof and prevents electricity leakage. The heater is protected with shockproof soft package material in case of unexpected damage during transportation. 1 Year Blast-proof Replacement Warranty. Measures 8.6" x 1.2" (L x D). Stick-on Thermometer: Simple to read and easy to attach (just peel and stick), Measures 5.2 by 0.7 and measurement range is 64F - 93F. With color indication design, the water temperature that the thermometer reads will change from white to blue. Made of 1.5 mm extra thicker Quartz Glass The double insulated heater is shatterproof and IP68 waterproof The heater must be fully immersed and should be placed vertically in the aquarium, rather than horizontally. You can easily install it by attaching the 2 suckers to the glass. By using this Thermometer, you will be able to monitor and maintain a suitable temperature that directly affects fish&#039;s health. An easy to identify blue color shows the current temperature of your aquarium water.