Compared to other similar products on the market, our fish tank heater is designed with an adjustable knob, which brings you more convenience to adjust the temperature from 18 Degree Celsius-32 Degree Celsius according to your actual needs. There are strong suction cups on the high-power fish tank heater, so you can attach it to the tank walls easily and conveniently, saving a lot of time and effort. It is constructed of glass material. With temperature display, with temperature probe at the bottom of heating rod, precise temperature control. There are 5 different styles for you to choose from. This product is perfectly suitable for home, household, dorm, aquarium and more. Item Name: Fish Tank Heater Material: Glass Power 25W/50W/100W/200W/300W Line Length 1.2 Meters Temperature Control 18-32 Degree Celsius Features: Adjustable, Practical, Waterproof Size Details: Style A: 18cm x 3cm x 3cm/7.09" x 1.18" x 1.18" (Approx.) Style B: 18cm x 3cm x 3cm/7.09" x 1.18" x 1.18" (Approx.) Style C: 21cm x 3cm x 3cm/8.27" x 1.18" x 1.18" (Approx.) Style D: 27.5cm x 3cm x 3cm/10.83" x 1.18" x 1.18" (Approx.) Style E: 31cm x 3cm x 3cm/12.2" x 1.18" x 1.18" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. 1. Must be used for diving and not allowed to be exposed outside. 2. Regional differences can affect the same power heater effect in different places will be different 3. It is not recommended to place it in a place where the water flow is very urgent, or it will cause heat loss. 4. The closer the heating rod is, the higher the water temperature 5. The water temperature in the aquarium varies from day to day and night. 6. The heating rod power is better for the corresponding fish tank 7. For freshy water and seawater. Package Includes: 1 x Fish Tank Heater(Random Logo)