Feature: 1. Small size, lightweight, convenient for you to install and remove. 2. Using high quality materials and exquisite craft, durable, can use for a long time. 3. With perfect heat dissipation effect, can effectively prevent engine from overheating. 4. Speed can achieve 28000rpm, special designed for RC 540 type brushless motor. 5. Three colours for you to choose, to meet different needs and requirements. Specification: Condition: 100% Brand New Item Type: Cooling Fan Material: Aluminum + Plastic Optional Color: Gold, Red, Silver Input Voltage：5-9V Highest RPM：28000 RPM Compatibility: Suitable for RC 540 Type Brushless Motor Designed Weight: Approx. 19g Size: Approx. 30x30x10mm/1.18x1.18x0.39inch Cable Length: Approx. 285mm/11.22inch. Package List: 1 x Cooling Fan4 x Screw Note: 1. Due to manual measurement, please allow 1‑3mm error, thank you！ 2. The picture may not reflect the actual color of the item due to the differences between different displays3. The connection wire has positive and negative poles. The wrong connection will not work4.Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.