Very small size,light weight  915Mhz frequency band    433Mhz frequency band  Receiver sensitivity to -117 dBm  Transmit power up to 20dBm (100mW)  Transparent serial link  Air data rates up to 250kbps  Range of approx 1 mile with supplied antennas  Demonstrated range of several kilometers with a small omni antenna  Can be used with a bi-directional amplifier for even more range  MAVLink protocol framing and status reporting  Frequency hopping spread spectrum (FHSS)  Adaptive time division multiplexing (TDM)  Support for LBT and AFA  Configurable duty cycle  Built in error correcting code (can correct up to 25% data bit errors)  Open source firmware  AT commands for radio configuration  RT commands for remote radio configuration  Adaptive flow control when used with APM  Based on the HopeRF HM-TRP radio module, featuring an SiLabs Si1000 RF microcontroller.    Specification:  Item Name: 3DR Radio Telemetry Module  Band: 915MHz    433MHz  Antenna connectors: RP-SMA connector  Power: 500mw  Sensitivity: -117dBm sensitivity  Interface: Standard TTL UART  Connection status: LED indicators  Net weight: 63g  RadioTelemetry Air Module Dimension: 51*30*10mm/12g  RadioTelemetry Ground Module Dimension: 70*25*12mm/15g    Package Included:  1 X Radio Telemetry base station (USB Connection)  2 X 500mw Radio Telemetry  1 X lead set  2 X Antenna