aqua miracle Black 10W Betta Heater with Temperature Control Small Aquarium Heater

Compact black mini heater with adjustable temperature control. Ideal for up to 1 Gallon Tanks. AquaMiracle Adjustable 10W Betta Heater Small Aquarium Heater Submersible Fish Tank Heater 5V/2A USB Powered Super Mini Aquarium Heater with Digital Display Thermostat.