Pair of split bamboo percussion sticks, 24" and 20"; two lengths for two pitches.  Each with a tuning hole. When the split ends are bounced off the palm or knee, they buzz. The buzz is due to a crack that goes most of the way down the instrument. That crack is meant to be there.  

Slide the colored string up or down the length of the crack to create more or less buzz and to change the pitch. A small hole near the bottom is covered and uncovered by the thumb to produce a wah-wah effect.    

Natural cracks will develop in the bamboo. This only adds to the awesome buzzing sound.  Also known as Buzz Sticks, BungKaKa, or Balingbing these split bamboo sticks were traditionally used in the Philippine Islands. They can be played in ensembles for the Kayabang dance; with separate players each playing one stick. In villages, people walking along carried the devil chaser to scare away animals (or spirits) in their path.