George Risk Industries MMF-875 Replacement Magnet

Product Description

The George Risk Industries MMF-875 is a small rectangular magnet used as a component in magnetic door and window contact security sensor assemblies. Measuring 0.125 x 0.375 x 0.875 inches, this magnet serves as the actuating half of a two-part reed switch contact set. When aligned with its corresponding reed switch, the magnetic field holds the circuit in its normal state. Displacement beyond the rated gap triggers the switch, signaling an open door or window. Security and alarm technicians install this type of component during new sensor installations or as a direct replacement when the original magnet is lost or damaged.

This magnet is suited for residential and light commercial security and access control applications. It is typically surface-mounted or recessed into door frames, window sashes, or casings alongside a matching reed switch contact. The compact profile makes it practical for installations where space is limited or where a low-profile appearance is required. Each unit is sold individually.

Key Features

• Compact rectangular form factor at 0.125 x 0.375 x 0.875 inches for space-constrained installations
• Designed to actuate reed switch contacts in door and window security sensor assemblies
• Sold individually, allowing single-unit replacement without purchasing a full contact set
• Suitable for surface-mount or recessed installation in frames and sashes

Compatibility

Designed as a replacement actuating magnet for use with compatible magnetic reed switch contact assemblies in residential and light commercial security sensor applications.

Installation Notes

Installation is typically performed by licensed security or alarm technicians. Deactivate and disarm the security system before removing or replacing any sensor component. Proper gap alignment between the magnet and the reed switch contact is critical to reliable operation — consult the reed switch manufacturer specifications for maximum allowable separation distance. Secure the magnet with appropriate fasteners or adhesive as specified for the mounting surface type.