Hobby-Ace 3DR Radio Telemetry Kit 915Mhz Module Open source for APM2.5 2.6 Small size and Light weight (under 4 grams without antenna) Receiver sensitivity to -121 dBm,Transmit power up to 20dBm (100mW) 915Mhz frequency band,Support for LBT and AFA Built in error correcting code (can correct up to 25% data bit errors) More 3DR Radio Telemetry product is provided by us in Amazon.Bring your eyes into the sky and racing like a free bird, enjoy the ultimate first person view experience.