Relay Shield (ie 5V Quad Relay Module) is a small current signal control power equipment commonly used electronic module, enabling high-power single-chip control devices are widely used in SCM system to make smart home project; and can be directly plugged into the compatible the use of various types of motherboards, eliminating the patch cable troubles.
Feature:
1. Standard For Shield interfaces and shape
2. Can continue to stack other For expansion boards
3. 3 M3 screw positioning holes for easy installation
4. High Drive (5V or 3.3V) normally open contact closure
5. Onboard relay indicator (red)
Special Note: When using the For UNO board connected to it, because UNO USB interface is extremely high, should avoid green terminals are shorted its shell.