USB serial port control relay with serial port control, long life, and overcurrent protection. Newly upgraded advanced version featuring a new optocoupler protection circuit for interference prevention and high-speed transmission. The relay output terminal functions as an electronic switch to control circuit on/off states; there is no voltage output at the load end of the module. When the relay coil has no voltage, the relay does not engage, and the common terminal (COM) connects to the normally closed terminal (NC). When voltage is applied, the relay engages, connecting the common terminal (COM) to the normally open terminal (NO). Features USB serial port control. Relay path: 5V. Power supply method: Type-C interface or pin header. Control interface: Type-C interface or pin header. Microcontroller chip: GD32F103C8T6. Baud rate: 115200bps. LED indicators: Power indicator and relay status indicator. Circuit design includes overcurrent protection and optocoupler protection. Output type: Relay common terminal, normally open terminal, normally closed terminal. Load capacity: 10A/30VDC, 10A/250VAC. Product size: Approximately 58x32mm. Note: Slight variations in appearance, color, and printed characters may occur between batches but do not affect functionality. Color: As shown. Material: PCB. Model: DSTUR-T30 3 Channel. Package includes: 1 x Serial Port Control Relay (Type C), 1 x Type-C Cable (50cm), 1 x 10Pin 2.54mm Female to Female Dupont Cable (20cm). Contents limited to items listed above; other products not included. Note: Lighting effects and display differences may cause slight color variation between the image and the actual item. Measurement tolerance: +/- 1-3cm.