Feature:1. BUILT IN CHIP: Relay module built in stable USB to serial chip and microcontroller, serial debugging software can send serial commands to the computer to control the 8 relays on and off, you can also send commands to the serial port relay status.2. USB RELAY MODULE: The relay module has a 5V supply voltage and supports USB power or external power switch.3. ABS MATERIAL: The plate of the relay module is made of ABS, which has good wear resistance and insulation and long service life.4. SAFE TO USE: This relay module has over current protection and relay diode renewal protection, making your use more secure and safe.5. LONG SERVICE LIFE: With a long electrical life of 100,000 continuous connections, this relay will meet your long term use needs.Specification:Item Type: 8 Channel Relay Module Material: ABS, electronic componentsChip: On board 8 bit high performance microcontroller chipPower Supply Voltage: 5V, support USB power or external power switchOutput Type: Relay switch signal.Package List:1 x 8 Channel Relay Module Note:Pay attention to safety