This item is a HC-05 module slave and master two in one module, it uses the CSR mainstream chip, V2.0 protocol standards, compatible with master module" iexcl; cent;slave module"or master-slave(whole) module.Features- HC-05 module Slave and master two in one module.- Use the CSR mainstream chip, V2.0 protocol standards.- Module working voltage 3.3 V.- Potter default rate of 9600, the user can be set up.- Working current: matching for 30 MA, matching the communication for 8 MA.- Dormancy current: no dormancy.- Used for GPS navigation system, water and electricity gas meter reading system.- With computer and adapter, PDA, seamless connection equipment- Commercial Series: module board Series- With LED indicator light, use 150mA and 3.3V regulation chip.- With VCCGNDTXDRXD foot for the - With "Re-seach" button(ON/OFF/WAKE foot for it , external MCU outinput "High level" can control module to re-seach)- Compatible with master module" iexcl; cent;slave module"or master-slave(whole) module.- Input voltage: 3.3-6V.Note1.Input power supply 3.3~6V, Prohibit more than 7V2.No "Automatically prevent power supply peversing func", so please correctly connect power supply3.We advise to install " master module"4.The "State" is output foot for LED status, when "Unconnected", output "Pulse" ; when "connected", output "High level", we can determine the states from "MCU"5.If only the board , No any " Function "