First Alert SCO501CN-3ST Wireless Interconnected Combination Smoke and Carbon Monoxide Alarm with Voice Location, Battery Operated (pack of 1)

I have purchased a property that was lacking in the smoke alarm department and had no wireless interconnection and these were the first choice. They are very easy to pair and install. Fair warning though, they are loud. I wore my noise cancelling earbuds and even through those, I can clearly hear them. The quality is good, you can hear them clearly when they give the location of which one went off. These things are also very functional as I had unintentionally set them off less than a couple weeks of installation. They will save your life in a fire. I highly recommend getting these as they are worth the investment.

Update: A little cooking accident caused a lot of smoke (no fire). The nearest alarm went off properly, and all of the linked alarms went off as well. Silencing the alarm required holding down the silence button for five seconds or so, which silenced all of the linked alarms. This review is based ONLY on the installation and setup. I just installed 7 units. The installation is very easy...took me about 60 seconds per unit to install the mounting rings.. You'll need a Phillips head screwdriver and a drill with a 3/16 bit for the mounting holes. I'm pretty handy with tools, but there was nothing involved in this that a novice should have difficulty with. Follow the instructions for where they should be mounted. There is a "dead zone" where walls and ceilings meet. Smoke detectors are ineffective in that zone. The previous owner of my home mounted all of the old detectors right in the dead zone. Oops. The programming is easy IF you read the directions and follow them exactly. Women should do fine; men will probably have to try programming a couple times before they figure out which simple step they overlooked. (I got it on the second attempt.) If you are overdue for new bifocals like I am, you might need a magnifying glass. The programming took less than a minute per unit when I did it correctly. Use hearing protection while you are programming and and testing. Seriously. All of the units will be going off at the same time on the table in front of you. At 85 decibels each, it is extremely loud, My total project time for installing all 7 was about 45 minutes hour from opening the box to putting up my tools. My units are spread out over three levels of the house (one in the basement, two on the first floor, one in an upstairs hallway, and one in each of three bedrooms). No issues with them communicating with each other. I tested each one individually and made certain it was communicating with all the others just to be sure. Running up and down all the stairs 7 times was a good workout. Again, hearing protection is advised. I have no doubt we will all be awakened if we ever have a fire in middle of the night. I really like the voice feature. If I have an alarm I will not have to go running through the house to figure out where the problem is. It clearly enunciates which unit is going off. Hopefully I will never find out how they operate in an emergency. I will update if I have any operational issues.

I've used previous iterations of this Battery operated (Wirelessly Interconnected) Smoke & Carbon Monoxide Detector (w/voice) in the past and this unit (SMCO500V) lives up to its predecessor. It's simple to use and setup (provided instructions are read - to pair the units wirelessly to work together). - They're Loud...but Not too loud - thankfully. - The mounts are a standard design to other smoke detectors (that can screw into the ceiling apparatus) and thus no new mounts were needed to attach these units in my home. - Battery-wise: If these units function like their predecessors - I'm sure it will last for several months on the eneloop AAs which I have been using for smoke detectors over the years. - Battery drawers are easy to pull open and get the batteries out. Simply push upwards from the bottom (of the battery drawer) to release and swap your batteries. - Haven't experienced any false Alarms with these particular units yet...but will update this review if I do. - All in all, a good device that lives up to its predecessor 👍

Intertek Testing Certification on back of each detector (photo). Pairing and assigning room name not too complicated but suggest using ear protectors. Installed 8 in large house and they all go off at once. Mounting plates are approx 4 7/8", big enough to cover typical round ceiling box if needed (photo). More and more cities look for testing certification by UL or Intertek before passing permit inspections - even plumbing inspections. Both Intertek and UL have websites you can check to see if a particular product passed. I did not see any other interconnected detectors sold on Amazon (10/1/25) listed. If you're going to trust a smoke alarm to wake up your family in time to get out safely, might as well install ones that are tested and certified. Otherwise, why bother putting them in at all? I took off 1 star because they don't have enough rooms to choose from for voice notification feature.

Bought as a replacement unit. The item was delivered promptly and was able to sync with my other detectors easily.

I’ve had 7 of these detectors for about 6 months now. We are very happy with this system! They have gone off 3 times. Twice was in the kitchen when my kids overcooked breakfast. Was so happy to test them in that way. All detectors went off “there’s a fire in the kitchen!”. We removed the pan from the stove and fanned the kitchen detector with no problem. The third time it went off, my daughter left the window open in her bathroom on a cold day and took a hot shower. Then opened the bathroom door. A huge amount of condensation came out of the bathroom and the detector went off “there’s a fire in the hallway!”. As the condensation cleared and she fanned the detector it went off. My daughter was instructed not to leave the window open when she takes a shower. These detectors worked as we would have hoped! As far as set up - it was a little difficult and noisy. But we completed all set up in about 1/2 hour - with ear plugs. Lol! This was to replace a $3,000+ wired alarm system that we no longer wanted and needed to be replaced. VERY happy with this system!!