The Flat Guiro is ideal for all Cajons and is a great way to add the sound of a Guiro to your Cajon. Manufactured from durable, polystyrene material with evenly spaced ridges, the Flat Guiro produces an authentic quality sound, and easily attaches to the Cajon which acts as a resonator. Just Peel n'stick the Flat Guiro with the included adhesive and it will expand your sound.