Feature: 1. WALL MOUNTED DESIGN: Aquarium cooling fan adopts external wall mounted design, beautiful, small size, easy to install, does not occupy the fish tank space. 2. RAPID COOLING: Fish tank fan outlet adopts 45 degree angle design, for the water surface cooling faster, the water surface can be cooled down quickly. 3. ADJUSTABLE WIND SPEED: Aquarium fan is designed with USB connector, safer to use, with a switch at the bottom, you can adjust the wind speed of the fan according to your needs. 4. WITH TIMER: Fan can be used according to the need to connect the timer, more convenient to control the use of the fan time, four groups of mode cycle, only need to set once, automatic cycle every day. 5. EASY TO USE: Timer comes with a compatible socket at the bottom, easy to switch the conversion plug, the timer is heat resistant and not deformed, environmentally safe. Specification: Item Type: Aquarium Cooling Fan Material: ABS Use: Fish Tank Cooling Fan Maximum Air Volume: 4.5FCM Maximum Wind Pressure: 0.35 MmH20 Power: 2.5W Suitable for Tank Wall Thickness: 9mm/0.35in Suitable for Fish Tank: 30cm/11.8in Product Size: Approx. 13x7x2.8cm / 5.1x2.8x1.1in. Package List: 1 x Aquarium Cooling Fan1 x Timer Note: All data are measured manually, and there are certain errors in the measurement results.