DC12 V 120 db Continuous Sound Decibel Piezo Buzzer IC Alarm Speaker 2 PCS

Loud and easy to mount. Better than I expected.

Have bought these alarms multiple times because they Are Very Loud. Don't have them up close, pointing toward your face, when testing or you'll be sorry. I use them in conjunction with motion sensor PIR lights to make an extremely effective outdoor night time alarm. Much better to use than regular horns because they use way less power and sound like a siren. Highly recommend.

Wow, these guys pack a punch when testing!

Loud, do not expose to weather. This is my second set.

When other reviewers say this alarm is really loud, rest assured that they are not exaggerating. If this alarm goes off, your neighbors are going to hate you, but they will definitely hear it. I am setting this up for my neighbor whose home is being gutted and renovated. Two burglars trespassed onto his property last weekend looking for items to steal. Fortunately he was nearby and scared them off, but he wants something that will deter another attempt. He has Wyze Cams monitoring his property, so he's buying a Wyze Plug at my recommendation. I am setting up this alarm with a SmoTecQ 12V, 2A AC adapter (about $12 total for the alarm and adapter from Amazon). He has the Cam Plus service so that his Wyze Cams can detect human figures. The rest is just a matter of setting up the Wyze automation. The alarm's power adapter will be connected to the Wyze Plug. If a human figure walks into the camera's field of view late at night, the camera will activate the plug, and the alarm will go off for 60 seconds. My neighbor will get an immediate notification on his phone. He's also going to set up some bright floodlights that will turn on at the same time. If the alarm works as intended and deters another burglary attempt, I'll edit this review and provide some video.

loud with just a 9 volt battery

Just as described. And timely.

Wanted to test these out before installing to repel possums and raccoons from my barn (destructive little buggers). Other reviewers say they are loud, and they weren't kidding. They are FREAKING LOUD. I'm sure my neighbors that live a quarter mile away will hear these when they go off.