4-Channel 5V Solid State Relay Module (High-Level Trigger) for Arduino, Raspberry Pi & ESP32

The 4-channel solid state relay module is a 5V high-level trigger relay board that lets Arduino, Raspberry Pi, and ESP32 systems switch four external circuits from GPIO control, making it useful for home automation, robotics, test fixtures, and general prototyping. Using solid state relays instead of mechanical contacts, it provides compact electronic switching for projects that need reliable multi-channel control. This 4-channel SSR module is ideal when you want to expand a microcontroller into a simple four-output controller for automation tasks, timed switching, or computer-controlled electronics builds.