Product Specifications: 50W, 100W, 300W Size: 50W length 20.5 cm, 100W length 26.5 cm, 300W length 30.5 cm Color: Black Material: Glass Package Content: 1 x Aquarium Heater 1. Application Suitable for freshwater and marine aquariums, Betta tanks, frog habitats, newt enclosures, turtle tanks, aquaculture systems, glass containers, and hydroponic systems. 2. Intelligent Temperature Control Features automatic constant temperature regulation. The heater automatically powers off when the water reaches the set temperature (LED turns off) and resumes heating when the temperature drops below the set point (LED turns on). 3. Safety Features Fully submersible design constructed from shatter-resistant quartz glass. Includes automatic overheat protection with safety shut-off. 4. Installation & Operation Ensure the heater is fully submerged in water before operation. The adjustable temperature range is 15°C to 35°C (59°F to 95°F). Press the set button to adjust the desired temperature. For optimal performance, position the heater near the water flow outlet and ensure complete submersion. 5. User-Friendly Design Easy-to-adjust temperature control knob. Made with 2 mm thickened quartz glass, suitable for both freshwater and saltwater aquariums.