The DC5V 2 Channels Relay Module is similar to the 4-channel version but with two relay channels. It is suitable for projects requiring the control of two separate high-power devices, providing a reliable interface between microcontrollers.
The low level triggers the relay module's power indicator (green) and the 4-way relay status indicator (red). User-friendly interface design, all interfaces can be directly connected through the terminal leads. Four fixing bolt holes are provided.
This is an Active buzzer is present inside with shock source, so as long as the electricity will call 2 Program control convenient, single chip microcomputer a high and low level can make the sound, and the passive buzzer is can not do.