300 Watt Pro Series Submersible Aquarium Heater The Professional Aquarium Glass Submersible Heater, 300 Watt, provides accurate thermal control for freshwater and saltwater aquariums, aquaculture, terrariums and hydroponic systems! Heats 60 gallon aquariums to 100 gallon aquariums. Maximum strength Quartz Silica Tube is shatter resistant and more durable than conventional glass heaters. A gravel guard tube cap and advanced mounting bracket is included. Mounts both vertical or horizontal positions.The Blue On/Off LED indicator and temp setting is easily viewed from multiple angles.