1、Safe and Reliable: Made of premium ABS material, it has strong durability and safety guarantee, allowing you to control with confidence. 2、Efficient Control: The LCUS HID drive free USB computer drive free control switch relay module is an efficient and intelligent controller that can make your control faster and more accurate. 3、Strong Adaptability: It has a wide range of adaptability and is suitable for various circuit control and group control management. Prior to design, research was conducted to ensure that it is suitable for most circuits. 4、Easy to Use: No complex installation and configuration steps, no professional installation tools required, just plug in the computer USB port to use. 5、Automatic Protection: The module has overcurrent protection and relay diode freewheeling protection functions. There is a mechanism within the module that protects itself from harm when the current is too high. Item Type: Drive Free Relay Module Product Material: ABS Relay Output Port Description: The relay output terminal is equivalent to two independent single pole double throw switches, where: COM: Public terminal; NC: Normally closed end, short circuited to COM before relay engagement, suspended after engagement; NO: Normally open, the relay hangs in the air before being pulled in, and is shorted to COM after being pulled in. 1 x Drive Free Relay Module