Features: new and high quality High quality material selection, manufacturing long-life hydraulic bearing Low noise, heat dissipation, saving a quiet environment, making DIY so simple Multiple power supply modes meet the requirements. The USB fan supports a variety of power supply modes, and DIY is more casual and convenient: mobile power supply, mobile phone charger, computer USB interface, etc. Suitable for all kinds of routers and set-top boxes, mobile hard disks, etc. It can reduce equipment working environment temperature and prolong the service life of equipment as it has great heat dissipation. Specifications: Material:Plastic Rotating speed:3000RPM Size:8cm/12cm/24cm 8cm:Approx.8x8x4.5cm/3.15x3.15x1.77inches 12cm:Approx.12x12x4.5cm/4.72x4.72x1.77inches 24cm:Approx.24x24x4.5cm/9.44x9.44x1.77inches Cable Length:Approx.115cm/45.27inches Package Includes: 1 Set Cooling Fan note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.