BW&reg; Radiolink AT9 2.4GHz 9 Channel Transmitter and Receiver Radio System for FPV RC Aircraft Helicopter (Model 2) Full types control, " Aircraft" model type added DSSS, Vibration alarm, 3ms quick response 4096 precision, support S.BUS, USB online upgrade Control distance: 900 meters on the ground and 1.5Kms air Built in Mini receiver which support and compatible with FUTABA S-BUS