Temperature adjustable: USB micro-type cylinder heating rod for precise temperature control The temperature is set between 18-34℃, 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 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. Name:Aquarium Heater Specifications:25W temperature control display USB version Applicable scenarios:fish tank, aquarium Note:Due to different production batches, there are differences in printed labels, and there are some differences between the physical object and the picture, which does not affect normal use. Colour:Black Material:Plastic+Metal Package Contents: 2 x Aquarium Heater