The BT31U is a UHF Bluetooth Module from Amp'ed Rf. It is designed for applications such as remote control, data transfer, and audio streaming. It supports Bluetooth v4.2 and has a long range of up to 150 meters. The BT31U has On-board Omnidirectional Antenna, External Antenna Interface, UART/SPI/I2C Interface, 3.3V Operating Voltage and a >85 dBm sensitivity. Additionally, the module is compact, lightweight, and energy efficient, making it ideal for use in battery-powered wireless devices.