AST800 FIREFLY CORELESS MOTOR WITH 16-1 GEARBOX * Motor Length: 1.53" (39mm) * Weight: 12 grams * Motor Diameter: 10mm (0.39") * Best Efficiency: 83% @ 300mAh * Motor kV: 4300 rpm/V * Armature resistance: 2.1 ohms * No Load Current: 25mAh * Gear Ratio 16 to 1 * Shaft diameter: 2mm * Prop Size: 10x5 * Length: 39mm