RC33B NO Recessed Wired Window and Door Contact Sensor Magnetic Reed Switch White 4pcs Short overview A compact recessed magnetic reed switch designed for wired home security, access control and burglar alarm systems. Model RC33B uses a normally open contact to reliably detect door and window open and close events. The lowprofile white design fits discreetly into frames and comes as a set of four sensors. Key benefits Reliable intrusion detection: The magnetic reed switch provides a stable signal to your wired alarm or access control panel whenever a door or window opens or closes. Tamperresistant and discreet: Recessed installation keeps the sensor out of view and less accessible to tampering while maintaining a clean appearance. Stable wired connection: Hardwired wiring avoids false triggers caused by wireless interference and delivers consistent performance for critical zones. Easy integration: Normally open contact type is compatible with most wired alarm and access control systems that accept NO inputs. Economical multipack: Four sensors in white let you protect multiple doors or windows without extra purchases. Features and specifications Model: RC33B Contact type: Normally Open (NO) Form factor: Recessed wired magnetic reed switch, lowprofile white housing Pack quantity: 4 pieces Application: Window and door contact sensing for home security, access control and burglar alarm systems Installation: Recessed mounting in door or window frames with wired connections to alarm panels Compatibility: Works with most wired alarm control panels and access control systems supporting NO contact inputs Practical installation notes Recessed installation requires a small mounting hole in the frame for the switch and a matching hole for the magnet in the moving part. Ensure correct alignment for reliable operation. Wire the sensor to the alarm or access control panel according to your system manual. Typical connection uses two conductor wiring to the designated zone input. Test the switch after installation to confirm the magnet and reed align properly across the full range of motion. Use scenarios Home entry monitoring: Install on front and back doors to trigger your alarm when a door is opened unexpectedly. Window protection: Recessed sensors on groundfloor or basement windows provide concealed detection for vulnerable entry points. Small business access control: Protect storeroom doors, display cabinets or internal access points by wiring RC33B sensors to an existing alarm or access control panel. Why choose this sensor RC33B offers a straightforward, proven method to detect openings in doors and windows with a recessed profile that reduces visibility and tampering. Its normally open reed switch and wired connectivity make it suitable for integration into a wide range of wired alarm and access control systems, providing dependable performance for everyday security needs. What is included Four RC33B normally open recessed wired magnetic reed contact sensors in white Note Installation requires basic tools and wiring knowledge. Follow your alarm system manufacturer guidelines for wiring and zone configuration.