New 12V USB Relay 4 Channel Programmable Computer Control For Smart Home Specification This is USB controlled relay Board with 4 channels. It's used the HID technology, so no need to install any driver in windows system and you can easy to use. We also provide an application and the C++ develop library that you can easy to integrate this module to your project. This module can be used: 1. Home automation 2. Robotics Control 3. Control doors and windows via windows system 4. Controller power supply Application: 1. Supply the application code 2. Supply C++ lib and dll for building your own project (include usb_relay_device.dll, usb_relay_device.lib, usb_relay_device.h) Package Included: 1 x 12V USB Relay 4 Channel Programmable Computer Control For Smart Home New