Usage: TelecommunicationVoltage: 5VPower Source: DC: bluetooth relayLC 12V Bluetooth 4-channel relay module equip with SPP-C Bluetooth 2.1 slave module and 8 bit high performance MCU, you can control the relay with cellphone APP directly. Feature: EpoxyContact Load: Low PowerModel Number: bluetooth relay moduleThe function and characteristics:1, On-board N76E003/STM8S003 and SPP-C Bluetooth 2.1 module2, The relay can be controlled with APP3, Effective control distance(on open area): 10m4, Power supply: 12V5, On-board 12V, 10 A / 250 v AC 10 A / 30 v DC relay, 100000 continuously, Module with diode effusion protection, short response time6, On-board optocoupler isolation components, anti-interference is strongly7, On-board Bluetooth indicator and relay indicator LED8, On-board preserved UART debug interface( rate is 9600) and MCU interfaceInterface:IN+, IN-: 12V power inputTX, : UART communicationSWIM, NRST: MCU interfaceLED D2/D3/D4/D5(red): Relay indicatorLED D1(blue): Bluetooth state indicator, the description of D1 as :(1)It's means wait for establishing connection with the APP when D1 blink slowly(2)It's means the Bluetooth connect with the APP successfully when D1 on all the timecolour:blueMaterial:PCBsize:62.7*63.2mmPackage Contents:1 * 12V 4CH Remote Control Switch ModuleOnly the above package content, other are not included.Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.