Honeywell 5818MNL Recessed Mini Door/Window Contact
Overview
The 5818MNL is a magnetic contact transmitter designed for concealed door and window monitoring in access control and security systems. At 0.75" diameter × 3.0" length, it's roughly half the size of standard recessed contacts — the tapered cylinder form factor fits flush into door frames and window edges without protruding, making it useful for retrofit installations or aesthetically sensitive environments where a bulky sensor would be unacceptable. It combines a self-contained transmitter and reed sensor in one unit, eliminating separate magnet housings and simplifying installation.
Compatibility
The 5818MNL is compatible with all Honeywell 5800 series wireless devices and receivers. Verify your control panel or wireless receiver supports 345 MHz 5800-series sensors before ordering — this is a wireless transmitter and requires a compatible 5800-series receiver or hub to function. It is not a wired contact and cannot be integrated into legacy hard-wired door loop circuits.
Installation Notes
The sensor operates across 32°F to 122°F (0°C to 50°C) in non-condensing conditions — avoid high-humidity enclosures or spray environments. The magnetic gap is 0.5" (12.7 mm) between transmitter and magnet; ensure the magnet mounting distance is within this tolerance or the contact will not reliably trigger. Power is a single AAA Lithium battery (supplied) or AAA Alkaline battery — Lithium batteries provide longer life in wireless applications. The tapered design allows the transmitter to fit into recessed door-frame cavities; pre-drill or use the supplied template to seat it flush.
What's in the Box
- 1x 5818MNL recessed transmitter with integrated reed sensor
- 1x magnetic sensor element
- 1x AAA Lithium battery (installed)
- Mounting template and hardware for frame installation
