This single-channel relay module features optocoupler isolation, ensuring -level trigger support. It is designed as an expansion board, making it for electronic projects. The compact design allows for easy integration into different systems, providing reliable control for applications. Features -Color:Red -Material:Iron,plastic -Size: 5.00X2.50X2.00cm/1.97X0.98X0.79in - level trigger: supports both high and triggers, allowing users to control the module according to their specific needs -Optocoupler isolation: features optocoupler isolation to effectively protect the control circuit and the controlled circuit, ensuring safety -Expansion board design: designed as an expansion board, it can be easily connected and expanded with other devices -user friendly interface: all interfaces can be directly connected through terminal wiring, making it extremely convenient to use -Durable materials: made from durable materials, ensuring stability and reliability for longterm use without easy damage Package list: 4 pcs x 12pcs x (1 channel 5V red board) relay module