F110S VS F121 VS F121 Pro
Model F110S F121 F121 Pro
Picture 　 　  
Flight Mode AltHold Mode(Low-Speed), AltHold Mode(High-Speed), Stabilize Mode, Trigger Switch for 360 Angle Flips Mode AltHold Mode(Low-Speed), AltHold Mode(High-Speed), Stabilize Mode, Trigger Switch for 360 Angle Flips Mode AltHold Mode, Stabilize Mode, Manual Mode, Trigger Switch for 360 Angle Flips Mode
Camera Protector for Image Transmission The antenna of image transmission without protector may be cut by the propellers or easily broken off. The newly designed cover with specially developed mould ensures the fixed position of camera and antenna funtion and avoids the possible damage caused by putting in and taking out of the pack.
Propellers Protector Propellers protectors directly installed on the motors. The possible collision may make motor leaned or rip out motor wires. The propellers protetors  installed on the frame protect the props against collision and avoid the problems of bumping motors or ripping out wires caused by direct installation on motors.
Soft material limits the protection effect. The developed mould strengthen the props protectors and the square design prevents pilots from being hurt by propellers. The pattened dual notches make (un)installation easy.
Propellers need to be uninstalled first each time to install the protectors, making propellers loose and steps annoying. Dual notches installation reduces the tear and wear caused by repeatedly (un)installing propellers and ensures easy assemly.
Motor Crashproof Two thirds of the motor is exposed, making it easily get bumped and affecst the flight. It requires manual adjustment of the motor position from time to time. Two thirds of the motor is covered by the protector and ensures better persistence to possible collision and stable flight.
Battery Fixer Battey fixed with rubber band and easily drops if bumped  The black plastic fixer at bottom ensures battery well 
Battery Connector JST connector, difficult to plug in and disconnect  PH2.0 connector,  easy to plug in and disconnect 
The battery wire to the flight controller would be easily broken after multiple pullings The improved PCB design guarantees the battery wire weld to the flight controller and it won't be easily broken.
The angle of camera can be adjustable or not? Can not Can not Adjustable, 15 degree or 0 degree.
LED for Night Flight Can not Support the LED (green and blue) for night flight, it is easy to recognize the direction even flight at midnight.
Voltage Output Port for Timer No Yes, have one
Arm and Disarm Arm by push the throttle joystick to the lower right corner. Disarm by push the throttle joystick to the lower left corner. Arm by push the throttle joystick to the lower right corner. Disarm by push the throttle joystick to the lower left corner. Arm or Disarm by press the Switch of CH7