Honeywell 5818MNL vs 5800RPS

The 5818MNL is one of Honeywell's most popular recessed wireless door and window contacts. Often regarded as the alternative to the 5800MICRA, the 5818MNL is a sensor that uses a magnet to determine whether a window is open or closed. This is the more traditional sort of door and window sensor, and operates in exactly the same way that the 5816 and 5811, Honeywell's most popular non-recessed wireless door and window sensors operate.

The 5800RPS, on the other hand is what is known as a plunger switch. These do not use a magnet, but, rather, pressure to determine the state of a window or door. The 5800RPS's plunger is a bit round, which allows it to be used in swinging door/window applications (whereas some plunger sensors, such as Honeywell's wired 955PS, are more like buttons and would require that the door or window be a slider so as to not hit up again the side of the plunger switch when closing.

Some prefer to use 5800RPS switches in places where magnets are a bit more finicky. These applications might include steel doors, though there are magnets that work well in that sort of application. The downside to a plunger switch is that it operates on a spring. This spring can be worn down, and when it is, the plunger will begin to stick. This doesn't usually happen until after thousands and thousands of uses. But they do tend to wear out much sooner than the more traditional magnet-based sensors.