X-Sense Wireless Interconnected Battery Powered Smoke Detector Fire Alarm with Over 820 ft Transmission Range, SD19-W, Pack of 6

No problems linking and installing these six smoke detectors, replacing six very old firex detectors, both battery-only and battery-wired units. I've been frustrated for years late in the evening or middle-nighttime with one detector chirping because of a low 9-volt battery. Hopefully, these will indeed last 10 years (but even five years will be satisfactory).Linking one at a time is simple: Out of the box on a convenient table, with units mounted to their bases to be activated, press the button 4 times on one unit, then after it starts flashing (searching), press the button twice on another unit. Repeat for all units. Finally, test the links by holding down the button on any one unit continuously until not only does it start to alarm, but longer until others begin to alarm as well. All linked units begin to sound-off.Mounting was simple to the existing firex base mounts. For battery-only units, the X-sense holes were compatible. For battery-wired units, the firex bases serve as a convenient template for drilling holes in the X-sense bases that match the existing wiring box screws. I never had to open the screws/mollys provided by X-sense.Four units are upstairs, and two units are downstairs, separated by only about 30 feet straightline distance and through at least four drywall/flooring/carpet barriers. Mine was simple, close-distance linking without complications of extensive metal appliances or HVAC ducting. No problems here at all!

These smoke detectors work perfectly! Just as advertised. After setup of all 6, I tested them one at a time with real smoke and they all alarm together. I followed the simple setup instructions and was done setting them up in 5 minutes.The trick is to plug all the detectors into their bases on a table, and do the setup procedure. Putting the base onto the detector activates a switch on the back of the detector to "turn it on". They won't do anything until the bases are put on.After setting them up, then install them throughout the house.

Why did you pick this product vs others?:Easy to install and test, I'll write a new review if my house every catches on fire and let you know how they worked. Hopefully you'll never hear from me again.

They work great. I bought 1 six pack and two 3 packs. Although, one of the units in the 6 pack has something clunking (loose) in it. So 8m not using that one.

Great product! I believe we have 10, easy to install and connect to each other. Extremely loud when all going off at once.

Here is some advice for setting up a network. According to the directions, a package of 3 units should be already connected without syncing manually. Just install them to your wall or ceiling. To test, hold in the front button of one of units and don't let go, and the others should join eventually, although not all will begin at the same time, so hold in that button until the others join. Then test the others the same way to make sure all of them are in sync. If you need to sync manually, best to un-sync according to the directions before re-syncing. And when I say directions, read and print right off the website to make sure you have the big picture of what to do instead of relying on only what comes in the package.If you want to test the units before installing, make sure you snap them to the brackets or they won't be in the operational mode, because the brackets depress a switch on the back side. If you have already installed the brackets, you can put a piece of painter tape over the rear switch to achieve the same thing.

We put these up and made sure they were l connected per the directions, and we test them weekly per the directions, and today we had a house full of smoke from bacon in the oven and they never went off. Just to be sure I kite paperwork in fire and held the smoking remnants under each one and NO ALARMS SOUNDED. It was definitely smokey enough because our air purifier in the living room was bright red and showed poor air quality. Save yourself the money and most importantly DO NOT PUT YOUR LIFE AT RISK. This company should be removed from Amazon market.

They are linked together by bluetooth i guess. My contractor was cutting hard wood that smoked in the rear of the house and the one in my living room where I was sitting went off alerting me.