Stacks of thick pine wood textured with slats and holes. The wood pieces on this toy are individually cut in our workshop and every piece will be slightly unique. The wood is all kiln-dried, chemical free, and pollutant free. Expect slight variances in size, thickness, hole may be slightly off center, and edges may not be perfectly smooth. Our bird customers seem to enjoy them! A great foraging toy and beak conditioning toy for medium and large birds!