This heater uses a flattened mesh heating element wrapped around a mica core to transfer heat evenly through aquarium water. A click-set control dial lets the keeper dial in a target temperature in one-degree increments, while a top-view scale and a side sliding scale let the setting be checked from more than one angle. A built-in thermal switch shuts the unit off automatically if the internal temperature climbs above a preset limit and switches it back on once the water has cooled, guarding against overheating during normal operation. The entire unit, including the control dial, is rated for full submersion in the tank. A double suction mounting bracket is included so the heater can be attached securely to the aquarium glass in one of three viewing positions. It is intended for indoor aquarium use in either freshwater or marine setups. Setup involves fitting the suction cups to the bracket, sliding the bracket onto the heater body, and pressing the assembly against the inside of the tank wall before plugging in.