All flask have a hook to hanging it on a cage bars or tree. Great for all Rodents! It allows pets to pick seeds themselves like they do in the wild. Components:wheat, flour, nuts 10,5%, maize, oats flakes, husk-free oat, millet, black sunflower seeds, sorghum, buckwheat, kardi seeds, striped sunflower seeds, red millet, linseed.