3DR Radio Telemetry Kit 915 Mhz Module Open Source for APM 2.5 2.6 2.8

Features:
Very small size,light weight
915Mhz frequency band
Receiver sensitivity to -121 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 HM-TRP radio modules, with Si1000 8051 micro-controller and Si4432 radio module
Support OTG of Android Cellphones, and computer OTG. Antenna is 5.8G

Specifications:
Item Name: 3DR Radio Telemetry Module
Band: 915MHz
Antenna connectors: RP-SMA connector
Output Power: 100mW (20dBm), adjustable between 1-20dBm
Sensitivity: -117dBm sensitivity
Interface: Standard TTL UART
Connection status: LED indicators
Air Module Size: 51mmx29mmx9mm
Ground Module Size: 69mmx24mmx24mm

Package includes:
1x Air Module(915Mhz)
1x Ground Module(915Mhz)
1x 4Pin-5pin cable 150mm for APM
1x 4Pin-6pin cable 150mm for Pixhawk
2x 5.8G Antenna
1x USB cable