i use these to build Morse code practice boards and they are loud enough to hear and maybe to loud but for price work great .

I’m always looking for ways to improve the security system in my home, around my driveway, and on my property. I have covered most of the basics, with the components that I’ve already installed, but knew of one area that was lacking. I needed more attention-grabbing noisy alarms and flashing lights, some way to alert anyone passing our home, that help was needed here and now. Something to scare off evil deed doers and let the emergency responders know which house had called for help.I looked at this “High Decibel Alarm Siren” on Amazon Vine offered by Geekstory for review, and thought it could possibly be a candidate for the “attention-grabbing noisy alarms” job. I could mount several across the front of the house, wired together under the eaves where they would be protected from the weather. Some could be installed safely out of the weather, in 3D printed enclosures with a solar panel and battery for power, an ESP-01 for WiFi control, and holes to allow the wiring in and the sound out. These could be mounted to the several fence posts surrounding the vehicles, and to trees on the property. So, I made a request and they were delivered the next day.Here’s the rest so far:PHOTO 1: This time the Amazon bubble shipping envelope did not contain a cardboard box, instead I received an anti-static bag full of,PHOTO 2: these ten small piezoelectric devices that make noise when connected to… hmmm, the title and most places in the ad, as well as the label on the device all say “DC 3-24V”, but the second paragraph under the heading “About this item”, starts out “Working voltage: DC 3-24V; Rated voltage: DC 12V…”. That’s somewhat confusing, but I won’t lose any sleep over it tonight as I was planning on operating the wired (non-battery powered) alarms at 12Vdc, and the battery powered ones at 5Vdc using a single Li-ion battery with boost converter.PHOTO 3: At this point in the review, while it was fresh in my head, I grabbed a few components and put this circuit together per the statement above “Some could be installed… with a solar panel and battery for power, an ESP-01 for WiFi control…” making only one simple mistake. Look close and maybe you can see it, and of course this would require a circuit board, a case and some software but I’ll add it to the to-do list.I did connect one to a 9V battery and at first was not impressed, but I want to try connecting all ten of them to a power source, maybe that would do the trick. Remember, I’m trying to scare off an evil deed doer poking around my window at 4:00am or maybe considering sliding under my truck to relieve me of that catalytic converter… Perhaps forty or fifty of these all over the outside of my house and property, going on and off randomly along with several flashing red lights, might have the desired effect. Time will tell.Lastly, I want to thank Geekstory for making these available, and Amazon for the quick delivery.

This is a loud buzzer as expected. It is very easy to use by connecting it to DC power. It is very easy to control it using a micro controller such as ESP32 or Raspberry PI Pico. This is really good for DIY projects as as alarm.