Description:  -The main gear stripping problem in T-REX 700 is a serious issue that annoys most flyers as they have to change main gears every couple flights.  While most other 90-size helicopters use 1.0M main gears, this T-REX 700 is designed to use 0.7M main gears.  Lower module main gears have smaller tooth surface than larger module main gears.  MicroHeli is the first company to release the Derlin main gear and 1M steel pinion for T-REX 700 to reduce the main gear stripping problem.  Precision CNC Main Gear is much stronger than plastic main gear. The derlin main gears are true and unwobble.  Moreover, the new derlin main gear is produced with better material than stock main gear. This material will make the gear stronger and therefore it is not easy to wobble or strip. 
-The main gear is NOT a drop in replacement gear for stock T-REX 700 which has 164T.  -Same gear ratio as stock T-REX 700N 8.21:1-The new delrin main gear and pinion has same diameter as stock ones. Includes:  -Delrin Main Gear 115T 1M-Precision Ultra hardened 14T steel pinion 1M Requires:  -Loctite (#242 is recommended) all bolts when assembly into the auto-rotation hub.-Assembly Weight:  N/A Usage:  -T-REX 700N helicopters Instruction:  -Instruction included in the package Features: Increase module of the main gear and pinion to provide higher strength to withstand main gear stripping problem