HOVER DEBUGGING KEY HOW TO ENABLE FOR WLTOYS V930,V966,V977 HD

HOVER DEBUGGING KEY FOR MORE STABLE HOVERING LINK FOR V977 http://www.banggood.com/WLtoys-V977-Power-Star-X1-6CH-2_4G-Brushless-RC-Helicopter-New-Original-Package-p-914247.html?p=4G2004147940201303FC LINK FOR THE V966 http://www.banggood.com/WLtoys-V966-Power-Star-1-6CH-6-Axis-Gyro-Flybarless-RC-Helicopter-p-914250.html?p=4G2004147940201303FC LINK FOR V930 http://www.banggood.com/WLtoys-V930-Power-Star-X2-4CH-6-Axis-Gyro-Brushless-Flybarless-RC-Heli-p-914248.html?p=4G2004147940201303FC