Product Description: The HC-05 bluetooth module can be set as a transmitter or receiver. It can easily transfer the data through the wireless, without complex PCB layout or deep knowledge in the Bluetooth software stack. You can combine this bluetooth module with your system: MCU, ARM or DSP systems, SOC systems, Personal Digital Assistants (PDAs), Computer Accessories or other systems your want to use under bluetooth functions. The HC-05 bluetooth module can build a connection to other modules in two ways: as a master or as a slave. For example, a robot can be designed to be a master connected to a slave bluetooth module or as a slave board to make a wireless connection with a PC. Specification: Integrated Bluetooth Serial Pass-through Module Master-Slave 6 Pin JY-MCU anti-reverse High frequency: 2.4GHz With VCC, GND, TXD, RXD, EN, STATE foot for the Bluetooth Use the CSR mainstream bluetooth chip Bluetooth V2.0 protocol standards Input voltage: 3.6~6V; Prohibit more than 7V Fully compatible with Ard-uino High speed: Asynchronous: 2.1Mbps(Max) / 160 kbps, Synchronous: 1Mbps/1Mbps Incredible small size (about the size of a dime ), and RoHS Compliant TTL data transparent Transfer between a host Bluetooth device Works for Bluetooth TTL transceiver module which allows your target device to both send or receive the TTL data. Coverage up to 30ft. Built in antenna. Working current: matching for 30 mA, matching the communication for 8 mA Used for GPS navigation system, water and electricity gas meter reading system With computer and bluetooth, bluetooth adapter, PDA, seamless connection equipment . Package included: 2 x HC-05 bluetooth module.