 When installing any door window sensor, first locate the raised guides on one side of the sensor, which will need to match up to the raised arrow on the magnet when installed. The gap between the raised markings on the sensor and the raised arrow on the magnet should be less than half an inch. Ideally, the sensor should be placed on the fixed frame of the window and the magnet should be installed on the moving window. If this is not possible due to the size of the frame, it is most important to mount the sensor flush on the surface. Best practice is to leave a minimum of a fourth an inch gap between the magnet or sensor on the window and the edge of the window frame. Often, windows are hung out of square, or the vinyl, wood, or metal parts can swell due to weather conditions. Leaving a space will ensure that the magnet does not contact any part of the frame when opening the window, which could cause the magnet or sensor to be knocked off. Another best practice is to leave a half an inch to one full inch from the edge of the window in the closed position. This also eliminates any chance of the frame knocking the magnet or sensor out of place. Track the LARM monitoring services.