STANDARD X7 kits (#217001 & #217002) using parts (#217040 + #217171 + #217174 + #217175)
is fit for use with STANDARD X7 motor #217350 – GUEC GM-350S Brushless Motor (500KV).

*** Important Recommendation ***
If you are a competition pilot or your flight
style is EXTREME and if you use HIGHER POWERED Motor other than the
STANDARD motor that comes with the X7 (#217350 – GM-350S),
GAUI recommend upgrading (replacing) with part
#217170 – X7 One Way Main Gear Set (Strengthened Upgrade) to ensure your flight safety.