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. Throughout testings to select best material for the main gear, we finally chose this material over our famous blue material that we used to make upgrade gears for all of the helicopters. The CNC auto-rotation hub is also designed to house the clutch bearing securely and functions as a bigger and stronger base for the main gear. With the new design, the whole unit is now much stronger than stock set up. - At the center of the main gear is a new high quality NSK clutch bearing. NSK bearings are very high quality bearings which made in Japan and provide unsurpassed quality over stock bearings. Good clutch bearings will definitely play an important role in the true and smooth operation of the main gear. Throughout testings we finally conclude that NSK bearings are most suitable to achieve smoothness and true performance for the T-REX main gear. -The main gear itself is also available separately in case of need for replacement for lower cost. -This Precision CNC Main Gear is the very last necessary item for T-REX. It is designed to improve performance on the T-REX 450V2 helicopters. -The difference between the MH-TX4102V2 and MH-LT4102V2 is that the MH-TX4102V2 comes with high quality Japanese made NSK oneway clutch bearing and MH-LT4102V2 comes with normal ABEC-5 oneway clutch bearing. - Main Gear MH-TX4102MG still can be used on this MH-TX4102V2 and MH-LT4102V2 as replacement gear. Includes: -Precision CNC Main Gear -Precision CNC Auto-Rotation Hub -Precision High Quality NSK Bearing -Hardware included Requires: -Loctite (#242 is recommended) all bolts.. -Assembly Weight: 17.5 grams including auto-rotation hub and bearing Usage: -T-REX 450 V2/PRO helicopters Instruction: -Instruction included in the package Features: Precision 100% CNC machined aluminum and delrin for TRUE and ROUND main gear. Pre-assembly high quality NSK clutch bearing for TRUE and smoothness operation New CNC auto-rotation hub for better strength and rigid Stylish design to bring style into performance