For 2x6S or 12S LiPo with about 5800mAh Complete replacement of the mechanics 1002/1000 (including H145 1:5) with motor set 3323: 1st stage (Ord.No. 139/60:500/20): 60:16=3.75 2nd stage (Ord.No. 510/90:510/20): 90:20=4.5 Total reduction from motor to main rotor: 3.75*4.5=16.875