Magnetic Contact Sensor SATEL B-21-BR — cylindrical door/window reed switch, brown finish

The SATEL B-21-BR is a cylindrical magnetic contact sensor designed to detect the opening and closing of doors and windows. Its reed-type magnetic switch is housed in a compact, brown-finished body that fits into narrow frames and profiles. The sensor provides a simple normally-closed / normally-open magnetic contact interface suitable for integration with alarm panels and access-control inputs where a discreet, reliable state change detection is required.

Advantages

The cylindrical form factor allows installation in concealed or shallow mounting locations, while the reed-type mechanism ensures low power consumption and long service life due to lack of moving electrical parts. The brown finish matches darker frames and joinery, reducing visual impact. The sensor is compatible with standard wired security and automation circuits and offers straightforward mechanical mounting and wiring for rapid deployment.

Suitable for

• Monitoring residential or commercial doors and windows
• Integration with alarm systems and control panels
• Use in access-control installations to signal door state
• Concealed mounting in narrow profiles and frames

Key specifications

• Cylindrical reed contact design for magnetic state detection
• Compact dimensions suitable for narrow mounting spaces
• Brown exterior finish for visual matching with darker frames
• Wired electrical connection for integration with security inputs
• Suitable for normally-closed or normally-open wiring configurations

How to use

Install the sensor body on the fixed frame and align the magnet element on the moving sash or door so that the contact closes when the door or window is shut. Connect the sensor wires to the alarm panel or input module following the panel manufacturer’s wiring diagram for magnetic contacts. Test operation by opening and closing the protected element and verifying state change on the control panel or monitoring equipment. Ensure mounting screws and wiring are secured and that the gap between sensor and magnet remains within the recommended activation distance.

Usage recommendations

For reliable operation, mount the sensor in a location protected from direct mechanical impact and excessive moisture. Use appropriate wire gauge and secure cable routing to prevent damage; if installation is exposed to weather, provide additional protection or use suitable conduit. Verify compatibility with the target alarm or access-control panel and perform functional tests after installation.