The aquarium heater is small and the temperature is adjustable. It is suitable for seawater and freshwater 30-40 cm small fish tank.Features:Mini Heater: The fish tank heater is small the length is 12.5 cm the diameter is 1.8 cm.High Quality: The aquarium heater is made of high-quality quartz glass double seal material advanced design ensures safe operation.Quick and Easy Installation: Vertical or horizontal placement using Aquarium heater automatic temperature control 78 no need to adjust the temperature easy to operate.This fish tank heater should be 100% submerged into water. Power: 25W / 50W optional.Convenient and Safe: The aquarium heater has two suction cups for attachment to the fish tank.Both suiting for fresh or saltwater aquariums provide a constant warm environment for your tropical fish to stay healthy.Specifications:Item name: Aquarium heaterMain material: QuartzOptional power: 25W/ 50WVoltage: 110V-120V(US); 220V-240V(EU)Size: Length: 12.5 cm; Diameter: 1.8 cmSuitable for: 30-40 cm small fish tankNote:* There could be some deviations due to manual measurement or slight color difference owing to photographing condition. Thank you for your understanding.Package Information:Package size: 15*8.5*5.5 cmPackage Weight: 132gPacking List:1* Aquarium heater