Feature:  Works with any USB Bluetooth adapters.  Default Baud Rate: 9600,8,1,n.  Built-in antenna.  Coverage up to 30ft.  Bluetooth version: V2.0+EDR.  Operating voltage: 3.3V.  Default Baud Rate: 9600,8,1,n.  Signal coverage: 30ft.  Item size: 4.3 x 1.6 x 0.7cm.  Item weight: 3g.  Package size: 9 x 3 x 1cm.  Package weight: 8g.  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 "Research" button(ON/OFF/WAKE foot for it, external MCU output "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 x 3.98cm.     Note:  Input power supply 3.3~6V, Prohibit more than 7V.  No "Automatically prevent power supply reversing function", so please correctly connect power supply.  We advise installing "Bluetooth master module" .  The "State" is output foot for LED status, when Bluetooth "Unconnected", output "Pulse"; when Bluetooth "connected", output "High level", we can determine the states from "MCU".  If only the board, No any "Bluetooth Function ".     Package includes:  1 x Bluetooth module