The RFM66W-868S2 part from Hope Microelectronics is an RF transceiver module operating in the 868MHz frequency range. It is designed to be used in low-power, low-cost, short-range communication systems such as remote keyless entry systems, industrial monitoring, and home automation. The transmitter section features a frequency range of 868 – 870MHz and an adjustable output power from 0dBm to +25dBm. The receiver section features a high sensitivity of -122dBm at 4.8kbps, low power consumption of 6mA, and wide selectivity of 50kHz. The module includes an MCU interface (SPI) and also supports various modulation schemes such as ASK, FSK, GFSK, MSK, and OOK.