The Relay Shield is an Arduino compatible smart module with 4 mechanical relays providing an easy way to control high voltage. The max switching power is 90W DC for each channel. It can be directly controlled by Arduino/Seeeduino through digital IOs with external 7V~12V DC power supply. Standardized shield form factor enables smoothly connection with the Arduino. The shield also has four dynamic indicators show the on/off state of each relay. With this shield and the corresponding Arduino library, you can easily add the internet accessibility to your project.