This is the Traxxas TQi 4-Channel 2.4GHz Radio System with 5-Channel Receiver and Docking Base. FEATURES: Compatible with the iPhone 3G/3GS/4/4S or iPod Touch 2nd/3rd/4th generation (not included), self adjusting clamp accomodates most accessory cases Traxxas Link App (available free on the App Store) completely integrates user"s iPhone or iPod touch with the TQi transmitter allowing user to edit, share and save drive profiles, manage up to 30 models and view real-time telemetry with the use of sensors (sensors not included) When equipped with sensors, the Traxxas Link dashboard displays speed, RPM, transmitter voltage, vehicle voltage and more, when all sensors are used, up to 9 gauges can be viewed at the same time Drive Effects settings can be controlled by touching and dragging the sliders on the iPhone or iPod touch screen or enabling the Multi-Function knob on the transmitter Telemetry enabled 5-channel micro receiver with dual channel-1 inputs High 13ms frame rate and near zero latency for responsive control Built-in failsafe returns throttle to last saved neutral position if signal is lost Steering sensitivity and dual rate Braking percentage adjustment Steering and throttle sub trim INCLUDES: #6507 TQi Transmitter with Docking Base #6518 TQi 5-ch Receiver, TRAL6518 Four Foam Docking Base Spacers Instruction Manual REQUIRES: Downloading the Traxxas Link, available free on the App Store AA Batteries: Four for transmitter Servos of modeler"s choice iPhone or iPod touch Sensors if desired; RPM Sensor, TRAC6536 Long RPM, TRAM6520 Long Temp & Voltage, TRAM6521 Short RPM, TRAM6522 Short Temperature Voltage, TRAM6523 XO-1 Temp & Voltage, TRAM6524 Temperature, TRAM6535 jxs 05/04/12 ir/jxs updt jxs 10/11/12