The JUWEL heater safely and reliably ensures the correct temperature in your aquarium. Depending on room temperature and aquarium size, your JUWEL heater will achieve a water temperature of around +28°C. Because it uses top-quality contacts and shock-proof, heat-resistant borosilicate glass (safety glass), JUWEL adjustable heaters meet the highest standards in both function and safety and, as you would expect, are TÜV/GS certified.