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

These are very loud, on par with a smoke detector. They were easy to install and they are sensitive. My dog likes to look out the window and when she hit the window it went off. Definitely worth the price.

Ive used this product now for over 4 years on two different houses. I love the fact they have a warning sticker facing outside to scare any would be thieves. Also, there is a sensitivity adjustment unlike some other brands. My only false alarm out of owning 16 of these units may have been caused by a bird hitting the glass. Otherwise, you can place on glass doors and opening and closing of the doors do not set this devise off. If needed, the sound is very loud. Very happy and will buy again.

Louder than I thought it would be , easy to install, better quality than bid box stores.

We purchased these for an RV road trip through Washington knowing that the trailheads are often targeted inside the national parks. I accidentally set them off a couple of times and they are LOUD. I specifically purchased these ones because they are extremely easy to spot from the outside and they have a flashing light that couldn’t be missed at night. My only critique would be that they cannot be easily removed once attached (which might be a good thing for some people). Our RV was a rental so they needed to come off and I had to pry them so hard I was nervous it would bust the window. It would be a good option to have some that suction on instead.

Works well and is loud. Definite deterrent.

I pounded on the window but no alarm went off but easy to set up just hope they work if there is glass breakage

Peace of mind for $27. Can't beat it

Nice sensitive device that emits loud noise when window glass breaks, giving you advance warning of a break-in at hone.

They do work especially if I open the patio door and forget to turn it off! The flashing light is hopefully a deterrent and the sticker on the back that goes against st the wi down another warning. Highly recommended

One of the teeth is broken

Works great

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.

Muy bueno la alarma se escucha bastante fuerte, solo aveces he probado y no se activa, no se si necesite mas sensibilidad