Temperature adjustable: USB micro-type cylinder heating rod for precise temperature control. The temperature can be set between 18-34, accurate to 0.1 degrees, providing the ideal temperature for fish. Compact design: Small size, as compact as a thumb, does not occupy space, suitable for mini fish tanks and micro-tanks with a water capacity of up to 4L. Heating element: Features a nickel soldering electric heating wire filled with high-density conductive material for efficient heat distribution, ensuring rapid heating and energy savings. Application: Specifically designed for small aquariums, space-saving and ideal for both freshwater and saltwater tanks. Resistant to acid and alkali conditions. Quality tested: Undergoes a strict selection process from material sourcing to design to ensure reliability and performance. Product name: Aquarium Heater Specifications: 25W temperature control display, USB powered Applicable scenarios: Fish tank, aquarium Note: Label printing may vary slightly due to production batches. Minor differences between the product image and actual item may occur, which does not affect functionality. Color: Black Material: Plastic and metal Package contents: 1 x Aquarium Heater (Other accessories not included) Note: Due to lighting effects and monitor settings, the actual color may vary slightly from the image. Measurement error allowed within +/- 1-3cm.