This item has been on DISCONTINUED. We recommend trying Hydor
Hydor Mini Heater Aquarium Heater (7.5 watts)
helps increase by a few degrees Fahrenheit/Celsius the water temperature of mini aquariums compared to the room temperature where they are positioned.
Extra small: easy to hide in mini-tanks and bowls
Super safe even under-gravel - no shock risk
Completely submersible, ideal for use in both glass and acrylic tanks