Readytosky 3DR Radio Telemetry Kit 915Mhz 100mW Air + Ground Module Open Source for Standard Version APM2.6 APM2.8 pixhawk 2.4.6 2.4.8 Flight Controller Support OTG of Android Cellphones,and computer OTG. Antenna is 5.8G level. The latest 3DR digital design, wiring complete, plus a separate shell, more secure, beautiful, more stable data transmission. The 3DR Radio telemetry system is designed as an open source Xbee replacement radio set, offering a lower price, longer range and superior performance to Xbee radios. It's availabl in 915Mhz; and in the following configurations: serial board (for the air) and USB (for the ground). This 3D Radio Telemetry Kit is small size,light weight(under 4 grams without antenna). If you need download drivers,please check this link  https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers