Features: --Temperature adjustable: USB micro cylinder heating rod for precise temperature control The temperature is set between 18~34 \u00b0 C, accurate to 0.1 degrees to give the desired temperature for fish. --Compact: As small as a thumb, it does not take up space and is suitable for mini fish tanks and micro tanks with a water capacity of up to 4L --Nickel soldering electric heating wire: a new type of nickel soldering electric heating wire, filled with black gold sand to surround and heat up, fully converting heat energy, quickly accumulating energy and saving electricity --Application: It is specially designed for small fish tanks and does not occupy any space. Acid and alkali resistant, universal for fresh/seawater tanks --After Tested: We are always committed to providing you with better products. We went through a very strict selection process from material to design. Description: Name: Aquarium Heater Specifications: 20W USB version, 25W temperature control display USB version Material: stainless steel Size: 7 x 2cm Applicable scenarios: fish tank, aquarium Packing list: Aquarium Heater x 1 Key: _x000D_