Description: -The Precision CNC Main Gear with Auto-Rotation Hub is designed to improve the performance over stock main gear. The main purpose of this upgrade is to provide true, round and un-wobbled main gear. The complete set comes with a new designed CNC main gear with better material than stock main gear. This material will make the gear stronger and therefore it is not easy to wobble. It is produced by CNC machines so it is absolutely true and round. With the new design, the whole unit is now much stronger than stock set up. -The main gear itself is also available separately in case of need for replacement for lower cost. Includes: -Precision CNC Main Gear -Precision CNC Hub -Hardware included Requires: -Loctite (#242 is recommended) all bolts.. -Assembly Weight: 12.3 grams including auto-rotation hub and bearing Usage: -E-flite Blade 400 helicopters Instruction: -Instruction included in the package Features: Precision 100% CNC machined aluminum and delrin for TRUE and ROUND main gear. New CNC hub for better strength and rigid Stylish design to bring style into performance