The TSIR series Bluetooth relay board with optically isolated inputs and OLED display and temperature sensor port. Very powerful and easy to use. You can easily control the relay board by your computer or smartphone using Bluetooth.The TSIR series relay provides four volt free contact relay outputs with a current rating of up to 10Amp each. The module is powered from a 5V(12V) DC power supply.The relays are SPDP types. Here is the Bluetooth APP for TSIR series Bluetooth Relay Module. You can use this APP control the relay module easily.