Nobiqfoq strives to provide safe and reliable aquarium products for all aquarium enthusiasts.We are always working to innovate and optimize our products. Nobiqfoq heater can automatically adjust(68°F~93°F) and constant water temperature to create a more suitable environment for the fish.This ensures that the fish does not feel too hot or too cold.We use thicker explosion-proof glass to increase the stability of the heater.Give your pet fish a comfortable home. Package Information: Aquarium heater x 1 Simulated aquatic plants x 2 Specification: 25W:7.9" for 5~10 gallons tank 50W:7.9" for 5~15 gallons tank 100W:10.2" for 15~30 gallons tank 150W:10.2" for 30~45 gallons tank 200W:11.9" for 40~55 gallons tank 300W:13.3" for 50~70 gallons tank NOTE: *Fully submerged in the water to avoid dry-burning and damage. *For a more constant water temperature,place the heater in a position where the water circulation is sufficient. *Please let it cool down for over 30 minutes before taking heater out of the tank. *The heating efficiency may be affected by the air temperature, water temperature and tank size. You can adjust ±1~2? to reach the set temperature.