6pin anti-reverse, integrated Bluetooth serial pass-through module, wireless serial. With wiring harness.
The HC-05 can be configured as either a Master or a Slave device, whereas its brother, the HC-06, can only be used as a Slave device. 

Add bluetooth to your project with the HC-05 BLUETOOTH MASTER MODULE and get access to a simple Rx/Tx pipeline through classic bluetooth protocol. The HC-05 module itself is mounted onto a breakout board which provides easy, breadboard friendly 0.1" headers for Power, Ground, TX, RX, and enable pins. The breakout board also provides a 3.3V regulator so you can power it with 5V from an Arduino or other 5V board.
Range - With a range of 30ft (~10m) 
Frequency: 2.4GHz ISM band
Warning: do not connect the power to the signal Pin, it will directly burn out the module!
Input voltage no more than 7V!