Just search for personal distress alarms, you can get them for $12 on Amazon (yuck), ~$5on AliExpress, and there are retail stores around me that sell them for ~$15-30.
Most run at 130db, but the battery size, rechargeability and various other parameters vary a lot. If they are going to be treated as disposable, cheaper is better
Just search for personal distress alarms, you can get them for $12 on Amazon (yuck), ~$5on AliExpress, and there are retail stores around me that sell them for ~$15-30.
Most run at 130db, but the battery size, rechargeability and various other parameters vary a lot. If they are going to be treated as disposable, cheaper is better