Specification: Note: its HC-05 Bluetooth module Slave and master two in one module this module can be set to a transmitter or receiver, transmitter could pairing with receiver, receiver and receiver or transmitter and transmitter can't communication between, receiver could pairing with computers and cell phone Bluetooth, when buying, the default for receiver. 1. It is HC-05.2. Use the CSR mainstream Bluetooth chip, Bluetooth V2.0 protocol standards. 3. Module working voltage 3.3 V. 4. Potter default rate of 9600, the user can be set up. 5. with computer and Bluetooth adapter, PDA, seamless connection equipment 6. Working current: matching for 30 MA, matching the communication for 8 MA. 7. Dormancy current: no dormancy. 8. Used for GPS navigation system, water and electricity gas meter reading system. Commercial Series: Bluetooth module board Series With LED indicator light, use 150mA and 3.3V regulation chip. With VCC GND TXD RXD foot for the Bluetooth With " Re-search" button (ON/OFF/WAKE foot for it, external MCU out input " High level" can control module to re-search) Compatible with Bluetooth master module slave module or master-slave (whole) module. Input voltage: 3.3~6V Size: 1.55cm*3.98cm Package Included: 1 Piecesx HC-05 Bluetooth module with backboard 4 x female to female jumper wire cable.