Aqueon Preset Heaters require no adjusting! The preset temperature has been calibrated to 78, appropriate for most tropical fish. The fully submersible heaters are constructed of shatter-resistant quartz glass and features an automatic safety shut-off to avoid overheating. An LED indicator light displays red when actively heating.

• Preset to 78, accurate to +/- 1
• No adjustment required
• Shatter resistant
• Auto shut-off
• LED light turns on when aquarium water is being heated
• Disclaimer: Variations in room temperature may cause slight deviations in the actual water temperature