Features: 1. Waterproof design ensures safe operation, which extends its service life. 2. CNC machined billet, secondary oxidation treatment for exquisite appearance. 3. High purity copper windings to ensure maximum efficiency, heat resistance 180-200°C. 4. Superior bearing is precision and durable with low noise and small friction. 5. Ultra-thin silicon steel sheet: excellent performance, high magnetic permeability, high silicon content, good insulation and heat resistance. 6. Rotor dynamic balance is controlled within 10mg, ensuring no noise, no vibration for smooth operation. Spec: Condition: 100% Brand New Item Type: RC Accessory Material: Metal, Electronic Originals Color: Red Optional Type: 2900KV, 3500KV Model: 3665 KV(rpm/volt) 2900 3500 Max voltage <16.8V ＜13V Max amps 80A 92A Rotor poles 4 4 io 3.8A 5.2A Resostance 0.0061 0.0037 Watts 1400 1400 Max. rpm 70000 70000 Length 65mm 65mm Diameters 36mm 36mm Weight(g) 245 245 Shaft(mm) 3.175mm 3.175mm Length of extend shaft