MC38 Door Window Magnetic Switch Sensor Normally Closed 2025 Product overview The MC38 is a normally closed magnetic switch designed for wired home alarm systems. It provides a simple, reliable way to detect door and window openings and integrate that input into alarm panels that accept NC sensors. This compact sensor is a practical choice when you need consistent performance without complicated setup. Key benefits Reliable detection: Normally closed contact stays closed when the door or window is shut and opens when the magnet moves away, providing a clear open or closed signal to your alarm panel. Broad compatibility: Works with most wired alarm systems that use normally closed door and window sensors. Compatible with standard NC input circuits. Easy installation: Compact, lowprofile housing fits most frames and sashes. Mounts cleanly on doors or windows for discreet security monitoring. Durable operation: Designed for steady, longterm switching performance to reduce false triggers and maintenance needs. Flexible wiring: Standard twowire connection for straightforward integration into existing alarm wiring. Features and attributes Model: MC38 Function: Magnetic reed switch for door and window open detection, Normally Closed (NC) Size: Compact, lowprofile form factor suitable for most residential and light commercial installations Material: Sturdy plastic housing for indoor use and everyday durability Performance: Stable switching action with clear open and closed signals for alarm systems Practical applications Front and back doors: Mount the sensor on the door frame and the magnet on the door edge to detect forced entries or unauthorized openings. Windows and sliding doors: Install on window frames or sliding door tracks to monitor openings on groundlevel access points. Cabinets and storage rooms: Use on supply closets, liquor cabinets, or equipment rooms where access should be tracked or restricted. What you get A compact, normally closed magnetic switch sensor ready to integrate with compatible wired alarm control panels. The MC38 delivers dependable open and closed state reporting for door and window monitoring in homes and small businesses. Installation notes Surface mounting works well on most door and window frames. Typical wiring is two conductors to the NC input on your alarm panel. Position the magnet and switch so they align when the door or window is closed for reliable operation.