These pendulums have a hollow chamber into which you can inserts a crystal or stone to increase a specific energy. You can also take a hair or piece of cloth belonging to someone related to the question. A great tool to increase the power of your dowsing.Silver pendulums come with a copper ring. 

Black pendulums come on a string instead of a metal chain. 

*Chain styles and pendulum point styles may vary and are subject to change.