FSK / GFKS technology, LoRa (remote) spread spectrum technology Half-duplex communication Super anti-interference (channel rejection ratio: 56db) High receiver sensitivity -139dbm. ISM multi-band, do not need to apply the frequency of free use. Multi-frequency optional, a variety of transmission rates. Can be used in FDMA and FM technology. Intelligent reset, low-voltage monitoring, wake-up time, low-power mode, sleep mode Low power receive current: 10-12mA 256-bit FIFO TX / RX RSSI channel detection function Transmission Mode: FIFO / Direct Mode (Recommended FIFO Packet Mode) Configuration: AFC / Wake on Air / Low Power / Carrier Sense / FEC Error Correction / AEC Encryption Ultra-long-distance transmission as far as 3KM open Colour:blue Material:PC+metal type:868Mhz Package Contents: 4 x Lora Module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.