Features: 1. Aquarium heater 25w 50w 100w 200w 300w, designed for different size of fish tanks. 2. Thickened Glass: Quartz glass, much safer for human and your lovely fishes, your pets will no longer fear the winter. 3. Adjustable and easy to use: The temperature of the aquarium heater can be automatically adjusted, and the heater temperature can be manually adjusted from 68℉ to 93℉(20℃~34℃) 4. Accurate Temperature Control: Set the required temperature, when the water temperature reaches the set temperature, the heater will automatically stop heating, when the water temperature is lower than the set temperature, the heater will automatically start heating 5. Easier installation:The top adopts a knob-type temperature adjustment. The heater is equipped with 2 suction cups, which can be fixed on the side wall or bottom of the fish tank. The suction cups are not easy to age and can be placed on the surface very firmly. Specifications: Voltage: 220-240V / 110-120v Wattage: 25W / 50W / 100W / 200W / 300W (Optional) Frequency: 50/60HZ Temperature Range: 20~34℃ / 68~93°F Material: Glass Application:Fresh and Salt water/ Caution: 1. We may send you a plug adapter((EU, US, AU, UK,etc) according to your country . If you need another type, please leave a message after ordering or contact us directly. 2. The heating rod must be totally immerged into water and no exposure is allowed. 3. When the indicator light is on, it is working. 4. Before cleaning the aquarium or heating rod, please turn off the power for 15-20 minutes to cool off the heating rod, or you will be burned.