The OASE HeatUp 25 Aquarium Heater is a high-quality, durable heater that is perfect for keeping your aquarium warm. With a glass construction and a fully submersible design, this heater is easy to install and maintain. The OASE HeatUp 25 Watt Aquarium Heater features an adjustable temperature control system that allows you to customize your heating needs. This heater is also UL listed and made in Italy, making it a quality product that you can trust.