Witch bells are a form of protection magick. Generally for protection against land bound spirits that may wish to cause mischief or harm. Commonly kept in rooms that need additional protection such as bedrooms and living rooms or on door handles to protect the liminal space between such places. They can offer an extra layer of protection, in some cases pre warning as the bells tinkle to say something is near and they look very beautiful. 
Each set of bells is unique and handmade. Different bells make a different tone of ring, and the colours and additional charms vary, you can choose based off your aesthetic attraction, your style of home or associations you would like to add such as pentacles are great for adding extra protection.
I can do custom sets, if that’s something you’re interested in send me an email and I can see what I can create.