The research

Smart smoke alarm

**Why you need it: **According to the National Fire Protection Association, 59% of home fire deaths result from the absence of a smoke alarm or the presence of a faulty one. This makes having good smoke alarms, whether smart or basic, essential. With smart smoke alarms, you can monitor the device status (without those 2:00 a.m. chirps) and get alerts about smoke and carbon monoxide even when you’re not home — and if you have a monitoring service, you can also get immediate help.

**Why we recommend it: **This hardwired detector can be used without a subscription, with a Ring Home plan, or with the standalone $5-per-month 24/7 Smoke and CO Professional Monitoring plan. (It also can be used with and without the Ring Alarm system.) With a monitoring plan, someone will call you in the event of smoke or carbon monoxide detection and/or will automatically send emergency services. An especially nice feature is that this alarm can interconnect with hardwired non-smart Kidde detectors: When I tested it using fake smoke, it triggered every hardwired alarm in my house, along with the Ring keypad and the base station. The Kidde Ring Smart Smoke Alarm is identical but without carbon monoxide detection.

Unlike with many smart detectors, you can silence this Ring model only by using a physical hush button on the device (unless the smoke subsides first). Also, if you pay for pro monitoring, and carbon monoxide is detected, emergency services will always be dispatched, even in the event of a false alarm.

**Another good option: **If you already have hardwired smoke/CO detectors and aren’t ready to buy a new one, Ring also offers the Ring Alarm Smoke and CO Listener. Unlike detectors, this device doesn’t detect smoke or emit sound itself. Instead, it “listens” for alarm sounds from your existing detectors. Should one go off, the listener alerts your Ring base station, sends a smartphone alert, and notifies your monitoring service (if you have a subscription).

Smart doorbell camera

**Why you need it: **A smart doorbell camera adds extra security, allowing you to screen who is visiting and to decide whether to answer — and whether to answer remotely through an app. It can also alert you to package deliveries. Most smart doorbells can easily replace an existing doorbell with one device that combines a ringer button, a video camera, a microphone, a speaker, and one or more sensors.

Why we recommend it: The Ring Video Doorbell Wired is a lot smaller than other Ring doorbells, which makes it easy to hide on a doorframe. It captures clear audio and 1080p video, and it’s accurate and reliable with motion and person alerts. This sub-$50 doorbell is cheaper than most Ring doorbells too, although it does require a Ring Home Basic plan to record anything. (If you have a monitoring plan, video storage is included.) And because it’s hardwired, you don’t ever have to worry about charging.

This model doesn’t work with traditional doorbell chimes (and the Ring Alarm won’t chime, either), so to have chimes sound in your house when the doorbell button is pressed, you need to add the Ring Chime or Ring Chime Pro or use an Amazon Echo smart speaker.

**Another good option: **If you don’t have existing doorbell wiring, the Ring Battery Doorbell Plus runs on a removable, rechargeable battery, though that makes it slightly bulkier. Or you can opt for an outdoor camera such as the Ring Outdoor Cam Plus, which is available in battery, plug-in, and solar versions. Both the battery-operated doorbell and the outdoor camera have a slightly better image and better AI than the wired doorbell but cost more and stand out a bit more around the front door.

Glass-break sensor

Why you need it: According to a survey from the Inter­nationalAssociation of Certified Home Inspectors, 23% of burglars enter through a first-floor window. And they don’t find an open one, they’ll make one.

A glass-break sensor monitors for specific sounds and sometimes even vibrations in order to tell when someone may be breaking a window. It then triggers the security-system alarm (and possibly law enforcement) to scare off intruders.

**Why we recommend it: **I’ve tested a lot of security cameras that can alert you to the sound of glass breaking. However, sometimes those sounds turn out to be from someone dropping something on the floor or even turning water on. The Ring Alarm Glass Break Sensor reacts only to the real deal, so you won’t ever have to worry about false alarms. How do I know this? Because after trying to trigger this thing numerous times using sound clips from YouTube, I broke out a hammer and got to smashing — and confirmed that only the real sound of breaking glass will trigger it.

Once it detects that sound, the actual sensor remains silent, but the Ring Alarm’s 104 decibels will start blaring away. I also received a smartphone alert within two seconds. As with any Ring Alarm event, you can disarm it in the app or via the keypad. And if you have the monitoring service, it will alert them too.

Open window and door sensors

Why you need it: Contact sensors, a standard way to monitor entry points in your house, consist of a magnet and a sensor — when the two are separated, your alarm is tripped. Open-window magnets are an add-on to the standard contact sensors that come with your basic system. They allow you to leave a door or window slightly ajar while still having your alarm system armed and at the ready, and they can send a notification when a family member is coming and going. I have also seen some pretty creative uses for them, including on liquor cabinets, medicine cabinets, and the refrigerator door.

**Why we recommend it: **My cat loves when we have the windows open a crack, but doing that always makes me nervous whenever I leave the house. (And this is even with a few security cameras going.) If you’re prone to leaving sliding doors and windows open when you’re at home and away, you should invest in a few Ring Alarm Open Window Magnets. It’s basically the same kind of magnet that comes with Ring Contact Sensors, and it allows you to have two magnets on the same window or door; that way, one sensor keeps you protected whether the window or door is ajar or completely closed.

Note that these magnets are intended to allow for a modest air gap of just a few inches, not a fully open door or window. Otherwise, someone could simply walk into your home undetected.

Flood and freeze sensor

**Why you need it: **According to the Insurance Information Institute, about 1 in 67 US households each year file an insurance claim related to damage from flowing water or freezing incidents. Those often happen in hard-to-notice and even harder-to-reach areas such as the basement, by the water heater, or behind the washing machine. Smart water-leak sensors can notify you the instant they detect water, by sending an alert to your smartphone. Many also detect drops in temperature to let you know about the potential for your pipes to freeze. Some have a siren or alarm or can be configured to trigger other devices, such as a security system, to ensure that you catch small problems before they become a big headache.

Why we recommend it: The Ring Alarm Flood and Freeze Sensor has the ability to detect a leak or flooding water, as well as to send word if ambient temperatures drop below 40°F. When either event occurs, the sensor alerts the Ring Alarm system, which can trigger different Chirp Tones (found under the sensor’s Settings) so that you can find the source of a leak or check on pipes that are at risk of freezing.

This is one of the few sensors on our list that do not trigger the base station’s siren or alert a professional monitoring service — though you can opt to send audio alerts from both the base station and keypad. (If you have a Ring subscription, you can also opt for an additional alert via an automated phone call.)

Backup power pack

**Why you need it: **One of the most common questions I get is: “What happens when the power goes out?” Most home security systems do have a bit of backup battery power, which can keep sensors and sirens running (and guarding) for a period if your power goes out. And if you have a monitoring plan, most of those subscriptions include cellular backup (or should — confirm that your subscription includes it). This power pack extends the built-in battery life of the base station so that even when power and Wi-Fi are down for an extended period, the system can still contact the monitoring service in an emergency.

Why we recommend it: Exclusively for Ring Alarm Pro users, the Ring Power Pack can keep your system running longer and at full capacity in case of a power outage.

The Ring Alarm Pro base station has a built-in battery that can provide up to 24 hours of backup power in the event of an outage, but only in low-power mode. That limits its functionality to the bare necessities, such as arming/disarming the system and triggering it in case of an emergency. The Power Pack, however, keeps the Ring Alarm Pro fully online when your Wi-Fi is available, and if it’s not, allows you to use the internet backup that’s part of the Ring Home Premium plan. Note that when fully charged, each Power Pack provides about eight hours of use to the Ring Alarm Pro and/or Eero 6 Extenders, depending on use. You can also stack three of them together, for a total of 24 extra hours.

This article was edited by Jon Chase and Grant Clauser.