Fangrui Product Details Whats Dry Contact Switch Module: The Dry Contact Module Is A Versatile Electrical Switch That Responds To External Signals, Controlling Other Electrical Equipment. With No Need To Worry About Directions Or Polarity During Installation, Simply Ensure The Correct Signal Current And Voltage Levels Are Maintained. Why Choose Dry Contact Module: Compatible With Mechanical Reset Switch And Rocker Switch,suitable For Various Mounting Boxes. Neutral Wire Is Required. App Remote Control: Turn On/off The Devices Effortlessly From Anywhere After Connected The Module To Tuyasmart/smart Life App. Convenient Voice Control: Just Need Simple Voice Commands To Trigger The Dry Contact Through Alexa/google Home Assistant,turn On/off The Device Effortlessly And More Conveniently. Enjoy Your Smart Life. Timer Schedule: With Flexible Timer Setting, You Can Trigger Connected Devices On Time While Saving Energy. Relay Status Function: With Relay Status Function, You Wont Have To Worry About Power Outages As You Can Set On/off/