AQQA Small Aquarium Heater

https://youtu.be/nBMCWny8A9A

AQQA Small Aquarium Heater,Submersible Fish Tank Heater Adjustable Temperature,Mini Short Dual-use Fish Heater with LED Digital Display Thermostat,Saltwater Freshwater 50W (Amazon Affiliate)
US: https://amzn.to/3QaPupv