HiLetgo HC-06 RS232 4 Pin Wireless Bluetooth Serial RF Transceiver Support Module Slave and Master Mode for Arduino Works with any USB Bluetooth adapters, running in slave role: Pair with BT dongle and master module. Led indicate Bluetooth connection status, flashing Bluetooth connectivity, lit the Bluetooth connection and open a port Backplane Core module uses HC-06, leads from the module interface includes VCC, GND, TXD, RXD, reserve LED status output pin, the microcontroller can be judged by the foot state Bluetooth has connected KEY pin slave invalid. Small size, low power consumption,high sensitivity for send and receive. Bluetooth version: V2.0+EDR &Operating voltage: 3.3V &Host Interface:UART &Storage Temperature:-40~+150&Signal coverage: 30ft &Item size: 4.3 * 1.6 * 0.7cm &Item weight: 3g. The module is mainly used for short-range data wireless transmission,such as Bluetooth wireless data transmission,Industrial remote control, telemetry,Traffic, underground positioning, alarm,Smart home ect. Industrial serial port bluetooth, Drop-in replacement for wired serial connections, transparent usage. You can use it simply for a serial port replacement to establish connection between MCU and GPS, PC to your embedded project and etc. Computer and peripheral devices.