The Hikvision DS-PD1-MC-WS is a fundamental component of a wired intrusion alarm system, specifically engineered to monitor the status of doors and windows. It consists of two parts: a permanent magnet and a reed switch. When the door or window is closed, the magnet keeps the reed switch in a specific state; once opened, the magnetic field is broken, triggering an immediate alarm signal to the control panel. This sensor is designed for indoor use and features a durable plastic housing that is both subtle and effective. Its small form factor allows it to be mounted on various types of frames without interfering with the aesthetics or operation of the opening. The device is highly reliable, offering a long service life and consistent performance for residential and light commercial applications.