Just to clarify you may find yourself cracking open the magnet side & removing the magnet from the plastic housing which is simply what I did- quick tip: I used white shrink wrap over the magnet to dress it up before I siliconed it to the window- works perfect & looks nice, with no ill operating effect at all!!!

Much cleaner look for double-hung windows than some of the SIXCT Honeywell sensors for the Lyric security system.