This is the Hitec 2.4GHz Basic Telemetry System Acro Pack. FEATURES: Compatible with Optima 7 and 9 receivers, Spectra 2.4 module and Aurora 9 transmitter Full telemetry system can transmit information to the Spectra module for display on LCD of the Aurora 9 and/or computer monitor (HPP-22 software is required) INCLUDES: HTS-SS (Sensor Station) - HRCM5832 HTS-MRMP (Magnetic RPM Sensor) - HRCM5842 Two HTS-TEMP (Temperature Sensors) - HRCM5834 REQUIRES: Installation into airplane, and setting up according to instructions COMMENTS: To activate full telemetry function, firmware upgrade is required for Aurora 9, Spectra 2.4 and Optima 7/9 as well as HPP-22. lmm 10.5.10 ir/jxs