Fielect 4" Alarm Bell DC 24V Fire Alarm Bell Stainless Steel Electric Bell Security Alarm Bell Internal Strike Type General Purpose Bell for School, Factory, Warehouse

I use this to ring in a pattern, I trained my dog to recognize it means I'm almost home from work. She'll start getting excited about 5 minutes before I pull in, so that way she's already about halfway through her excitement routine when I walk in the door. I then bought an 8" and 12" bell and use them for various automated notifications with my proprietary Arduino-based smarthome alert system. Current draw is low and it's not picky about voltage. It will ring at 12V (albeit at reduced intensity). Next I plan to create a xylophone with a set of hammers attached to servos to increase the number of sounds available.