This wood pendulum measures approximately 2 inches long.
The top unscrews to reveal a hidden chamber.

Attached to a 7 inches chain.
Can be changed to a silk cord on demand.

The top of these pendulums unscrew allowing us to put little things inside.
Herbs, a hair of someone related to the question, oils, a drop of water ( water transmits energies). 

Chamber pendulums allows us to attune the pendulum to the very specific questions we have or add a specific energy to it.