Review on 🔊 Industrial Electronic Alarm Buzzer Siren 105dB - uxcell LZQ-401K DC 6-24V 180mA: Product Overview, Features, and Reviews by Greg Simms

Note that this thing sounds like a fire alarm. Bought as a "bell" to alert employees to breaks on the schedule, but now everyone at the factory runs outside twice a day and queues at the playground. It says fear, and that's what it is. If you want a real alarm clock this one is great and loud. If you need an alarm and don't want to constantly explain that there's no fire, keep looking.