The ring alarm and ring sensors work very well, and for most they install as intended. This review is written for those of you that may have an install that doesn't work as intended. A few things ring should make loud and clear in their install docs. 1. If you buy multiple sensors absolutely do not pull any tabs or turn any sensors on until the last item you installed has completed. Give it a few minutes to be certain. The ring base is easy confused by 2 requests. 2. The app can be flaky. Change your phone timeout to never while installing. Several times on my s8 I had to start over because the screen turned off, and even though the last screen I was on came right back the app flaked out. 3. If a sensor doesn't immediately connect after your first try DO NOT try to add it again. Reset the sensor. Wait a few minutes. Delete it from the base. Chances are it communicated with the base and the base is in a weird state with that sensor. 4. You may have to reset new sensors, and then pair them manually. Even if you never attempted to pair them. 5. Before attempting to install any add ons outside of the base package of equipment that is pre paired for you, become familiar with resetting each component completely. I suggest printing out the guide to resetting them. The keypad and the base station are the most difficult. Ring support asks you to call them to reset the base anyhow and for the average user I would agree. Once I diagnosed the issues with mine and determined the base station was having an issue correctly pairing the devices I hard reset all of my equipment. I then added each piece manually and waited several mins between each piece to install the next. The system has been working great since then. Pro tip Most doors aren't flush. This causes mounting issues with the sensor. The slim part is simply a magnet encased in plastic and is easily removed. You can just mount the magnet which will mount inside nearly any door and trim and allow you to line things up.