The RFM26W-433S2 is an ASK, FSK, GFSK, OOK transceiver module manufactured by Hope Microelectronics. This module can transmit and receive data at radio frequencies ranging from 142 to 1050 MHz. It features a low power consumption, high sensitivity, and high data rate of up to 500 kbps in FSK modulation. The module also supports a wide range of modulation schemes, including ASK, FSK, GFSK, OOK, and Manchester. It uses SPI (Serial Peripheral Interface) technology for communication, as well as a built-in intelligent temperature control system. This module is perfect for applications such as retail egg-timers, garment tracking, and wireless alarm systems.