2 Channel 5V Relay Module

This board carries two independent electromechanical relays, each driven through an optocoupler so the low-voltage control side stays electrically isolated from whatever higher-voltage or higher-current load is being switched. That isolation protects a microcontroller's GPIO pins from the electrical noise and back-EMF that switching inductive loads like pumps, motors, or solenoids can generate. Two channels on one board is a practical middle ground for projects that need to control a pair of related loads, such as a watering system's pump and valve, or two separate lighting zones, without wiring up two single-relay boards. The screw-terminal relay outputs make it straightforward to connect real-world loads without soldering, and the standard 5V logic-level inputs work directly off an Arduino, ESP8266, or Raspberry Pi GPIO pin.