HappyModel HML650 Electric Retractable Landing Gear Control Module for Landing Skid Tripod DIY FPV RC Quadcopter Drone DJI This is Original Controller for Hml650 Retractable Land Gear. Effective Pictures, Product Do Not Include The Landing Gear and Quadcopter Set. Please Strictly Follow The Manual To Assemble and Use The Retractable Landing Gear. As We Have No Control Over Use, Setup, Final Assembly, Modification or Misuse If The Switch Channel On The TX Has Fail-Safe Function, Set The Fail-Safe Value To [Lower] Position, So That The Landing Gear Will Be In [Lower]Status To Land The Aircraft Safely. If The TX Needs To Restart After The Flight Controller Use Return To Home Function When Aircraft Out of Control, Please Be Sure To Put The Knob Switch Gear In [Lower] Status First.