YKS 3DR Radio Telemetry Kit 915Mhz Module Open Source for APM 2.6 2.8 Pixhawk RC Quadcopter Very small size,light weight (about 4 grams without antenna). Transmit power up to 20dBm (100mW), air data rates up to 250kbps. Support for LBT and AFA, 915Mhz frequency band. Adaptive flow control when used with APM. USB Interface reciever. Connect the PC tablet. Based on the HopeRF HM-TRP radio module, featuring an SiLabs Si1000 RF micro controller and Si4432 wireless module.