Shaker made from a large bean pod.
Like all idiophones, bean-pod rattles make their own sound from the vibrations of the material the instrument is made from without the use of reeds, strings and so on. In this case the materials knocking together, being 'concussed', make the sound.
This is a dried bean seed pod. The seeds inside rattle when it is shaken in the air. Can also be held in one hand and struck into the palm of the other. This one makes quite a loud sound as the pod and the seeds are very large.