ARRIS Radiolink AT9S 10CH 2.4GHz Transmitter + R9DS Receiver Support S-Bus PPM PWM for RC Airplane Quadcopter Helicopter (Free Battery Straps) This is the upgrade version for Radiolink AT9, preloaded with airplane, glider, helicopter and multi-rotor modes, easy and straight forward setup. Able to get data telemetry from R9DS receiver, S.Bus compatible, upgradable firmware through USB and vibration alarm. DSSS and FHSS spread-spectrum technology working synchronously, QPSK modulation support excellent anti-interference performance. Support S-BUS, PPM and PWM signal. Fast response, 3ms only, which is much less than the average 20ms even 9 channels act synchronously.