Temperature-setting button to preselect the desired water temperature within the range of 19°C to 31°C at 0.5°C intervals Water-tight cap, i.e. fully immersible Control light for the heating phase electronic switch for ultimate reliability and safety Extra thick (2 mm) heat- and shock-resistant borosilicate glass tube Twin ceramic heating element to ensure uniform heat dissipation through the glass Securely attached by two adhesive suckers Long mains lead (1.6 m) for simple installation in the aquarium Easy to read, ensuring user-friendly temperature setting