Window Alarm System 4-Pack – Ultra-Loud 120dB Alarms with Advanced Vibration Sensors – Window Security Alarms for Glass Break Detection – Features Low Battery LED Indicator

Very loud and great deterrent.
So here’s the deal. These things are a great addition to any home security system, or a great deterrent if this is the only security you have. Most home break in thrives do not want to be seen or heard. They also know there is no way to beat a stand alone window break sensor. If they see this in your front window they are just going to go somewhere else. And to me the blinking led is the best feature of this device. It’s a beacon to the thieves saying “I will hear you”.So how does it work? I have added a video showing me measuring the sound levels compared to the claims. My meter measured 115DB right next to the unit. That’s close enough to call the claim accurate. The video also shows the sound dissipation as you move away. The sound level is cut in half at about 10 feet. But unless you are a very heavy sleeper wearing earplugs, you are probability going to hear this go off in the dead of night.The fact that you get 4 for 25.00 is just icing on the cake. Put two facing the street In very visible places and two in the back on your sliding doors or windows. I am probability going to get another 4 to cover the rest of my windows. This is really a good product and I would definitely recommend it.FYI: I paid full price for this product and was not given any consideration for this review. In fact I search for “window break sensor” here on amazon and this showed up. Glad I found it. If you found this review helpful please indicate so below.

Crime Deterrent
May need to order more of these now. They work great! Other than a sonic boom that happened after install when they all went off. 😁They install easily, are very loud, and sense all vibrations nicely and sound the alarm. The red flashing light also is a great visual deterrent. It flashes every few seconds letting a criminal know it’s working. You will need 8 AAA batteries (2 per) that are not included. The warning stickers are also a good deterrent. I’m recommending these for ease of install and piece of mind. 👍

A bit large, but works for me
Super easy to install, but because they are so large you need to think about where you’re putting them. Make sure you can slide off the battery case when it comes time to replace the batteries. One of mine I stuck too close to the wall next to the window (live and learn!) and will probably have to peel it off when it comes that time because I didn’t think it through until AFTER I stuck it on. The adhesive is very strong! They are large, so if you want to put them on the stationary part of the window, make sure you leave enough room to open the window. I love the flashing red light, which is easily visible from outside, and lets people know that there is an alarm. I like to think this is a deterrent in and of itself. Even if it’s not, the alarm seems to be adequately sensitive. I have one on a living room window and was having new flooring installed. The installer dropped a tool near the window (it was a pretty loud bang when it hit the floor) and that set the alarm off. I was very relieved to know that it worked. Let me tell you, the alarm is LOUD! I heard it over the power tools the intallers were using–it got everyone’s attention. I mentioned the flashing red light–think about how that might be seen from inside your house before you install these, too. One of my alarms is in my living room and I had to place it so it won’t be seen at night from inside. That would be super annoyng. I can see where it could be an issue in a bedroom if there’s no curtain or other window covering that could block out the light. Overall, I am super happy with my purchase and I feel more confident that those vulnerable windows are less vulnerable now. I like that these use AA batteries, because I always have a number of them on hand, but that is what makes the alarms so large. So, bottom line, make sure the size of these alarms works for you and that the flashing red light won’t bother you. I would recommend this product.

They work!
Got these for downstairs windows and they work! Super easy to put up, red light flashes to indicate they are working, a solid red light will indicate low battery (off, low and high sensitivity settings). We have double-pain, double windows where one is fixed and the other one slides to the left. We put one unit toward the frame in the middle of one window, then went outside and banged against the opposite window and it did not set off the alert so I did have to put one on each side. Good news is, they are super affordable. Then I went upstairs to the opposite side of the house (each floor is 1850 sq ft) and I could hear the alarm with no issues at all (and we have heavy insulation in the ceiling/floor between floors). Perfect solution for what we needed!!!

One of the teeth is broken

These window alarms are excellent. We have an older home with a few basement windows. I installed one alarm on every window.Pros: good size, warning sticker and light alert that the windows are alarmed (and the light means you know if the batteries have power), can be placed anywhere, on-off switch, easy battery access, extreeeeeeemely loud (my cat set one off – it could be heard outside, throughout the house, and was so loud that I could barely think even with ears covered to go switch it off and back on), sensitive.Cons: unknown as to whether they can be removed and reused due to the sticker attachment. It would be nice if 3 were included per alarm.Highly recommend as an extremely easy, affordable, and quick security update. Anyone can install them.