Designed for larger aircraft the Optima 9 features two of our exclusive Boosted Omni-Directional Antennas for added safety and security. SmartScan Mode Selectable Low Battery Warning Basic Telemetry Function Full Telemetry Capabilities (Using the HPP-22 and Hitec Telemetry System) Fail-Safe/Hold Function Upgradable& Firmware Specifications Modulation: 2.4 GHz AFHSS Conversion Type: N/A English Metric Size: 1.92" x 1.14" x 0.61" 48.00 x 29.00 x 15.00mm Weight: 0.80oz 22.40g Detailed Feature Descriptions Adaptive Frequency Hopping Spread Spectrum Technology (AFHSS) The Optima 9 utilizes our AFHSS 2.4Ghz technology and our exclusive Smart Scan system to ensure a rock solid, interference free connection. When selected, Hitec?s 2.4GHz SmartScan function scans the 2.4GHz spectrum to find the cleanest channels in which to operate therefore providing interference free operation even in the most crowded environments. Dual Boosted Omni Directional Antenna (BODA) The Optima 9 receiver utilzes two of our exclusive BODA antennas to insure a rock solid connection between you and your plane. Independent testing has proven that the Dual BODA antenna system used in our 9 channel receiver is equal to or better than our competitor?s remote receiver or quad antenna systems. Supplementary Power Connection (SPC) With our Supplementary Power Connection you can eliminate ?brown out? concerns by powering the receiver independently of the servos.