The StarBird Brainiac Block is a stimulating and challenging toy that is designed with a bird's physical and mental health in mind. Handcrafted from untreated pine with a stainless steel eye hook and quick link, the block is a great way to provide hours of entertainment for your feathery companion. The layers of the Brainiac Block will entice your companion to chew when you insert slices of nut or pumpkin seeds, twine, ribbons, corn husks or other small and safe intriguing bits. Simply hang the block against the bars of the cage. Large is about 8", the small is about 6".