Specification: Origin: Mainland China Module Description: 1, The module adopts genuine high-quality relay, normally open interface load: AC 250V/10A, DC 30V/10A;. 2, The use of industry quality isolation optocoupler, anti-interference ability, stable performance; trigger current only 3mA; 3, Module operating voltage 5V 4, Low level suction; module contains a current limiting resistor, you can directly use the positive and negative control of the power supply, you can also use the microcontroller's I/O port control; 5, Power indicator, 16-channel relay status indicators 6, Interface design humanization, all interfaces can be directly connected through the terminal leads, very convenient 7, With 4 fixed bolt holes, easy to install Highlights: 1, With optocoupler protection. On-board power supply module does not require external power supply. i/o port drive low level effective. 2, Can be used as a microcontroller development board module, can be used as home appliance control, can also be used as PLC expansion output. Note: Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! Please allow 1-2cm measuring deviation due to manual measurement. Included: 1*Relay Interface Board 1.High-Quality Craftsmanship, Convenient Wiring: This 16-channel 5V relay interface board features genuine and high-quality relays. It provides easy and hassle-free wiring options, making your installation process a breeze. 2.Strong Interference Resistance: Equipped with industry-leading isolated optocouplers, this low level trigger expansion board boasts exceptional interference resistance and guarantees stable performance. With a trigger current requirement of only 3mA, it efficiently handles various electrical environments. 3.Stable Performance: The 5V operating voltage ensures consistent and reliable performance of the relay module board shield. Rest assured that your devices will be controlled accurately and effectively. 4.Low-Level Trigger: Designed for convenience and versatility, this low level trigger relay module supports low-level triggering. It includes current-limiting resistors, allowing direct control through the positive and negative poles of the power supply or via an I/O port on a microcontroller. 5.Optocoupler Protection: With built-in optocoupler protection, this low level trigger board offers enhanced safety. The onboard power module eliminates the need for external power supply, while the I/O port is driven by a low-level signal to ensure efficient operation.