Graupner 2.4GHz transmitters based on Graupners new HOTT 2.4GHz platform (Hopping, Telemetry and Transmission) with bi-directional communication between transmitter and receiver and superb telemetry support through HOTT telemetry sensors. HOTT transmitters feature voice output and an integrated earphone socket, providing you with clear and audible telemetry and facilitating total control and awareness of your radio controlled model. All telemetry data is stored on the included Micro-SD card. The graphical screen on Graupner HOTT transmitters is an eight-line display with blue backlighting for excellent brightness and clarity and programming access. Graupner HOTT transmitters are upgradeable using the included USB cable.