YukiHalu USB Powered Aquarium Heater, 10W/20W/30W Adjustable Mini Fish Tank Heater with External Temperature Controller, LED Display, Used for 0.5-1 Gallon Tank (10W USB)

The adapter must be larger than 2Amp current (5V 2A 10W)insufficient power of the adapter will cause no heating and the number will flashes or the controller restarts repeatedly, make sure the power adapter has enough power.
Is Discontinued By Manufacturer ‏ : ‎ No
Product Dimensions ‏ : ‎ 0.71 x 0.71 x 1.97 inches; 6.35 Ounces
Date First Available ‏ : ‎ December 10, 2021
Manufacturer ‏ : ‎ YukiHalu
ASIN ‏ : ‎ B09LM8S7WS

【Automatic Constant Temperature with 1℉ Accuracy】Thanks to advanced Intelligent Frequency Conversion Technology, the water temperature can be kept constant with an accuracy of 1℉. The heater’s working frequency will be changed according to temperature variation, and the heating is automatically stopped when the set temperature is reached. Compare to traditional heater, this new technology will cut down 49% electricity bill for you.
【Overheating Protection & DC 5V USB supply】The power will be cut off and stop heating automatically if the heater overheating. Protect your fish. Never cook your fish. USB 5V power supply, prevent electric shock. 30days full refund, 12-months warranty.
【External Temperature Controller, Never Wet Your Hands】Use an external controller to set the temperature instead of immersing your hands in water to rotate the dial. Never wet your hands or contaminating your tank. Easy to install.
【Built-in Temperature sensor, Power-off Memory Function】Dual built-in temperature sensor, the water temperature will be displayed on the external temperature controller in real time. No need to buy other temperature meters. The heater will remember the temperature setting, no need to reset the temperature after power off.