The Lixit Bulk Salt Wheels for Rabbits Guiana Pigs and Other Small Animals (Mineral Only) is a great way to keep your pets hydrated. These wheels are made of high-quality salt that is free of harmful chemicals and has a trace amount of calcium, magnesium, iron, sulfur, copper, cobalt, zinc, and iodine. They are also easy to clean and are a great way to add flavor to your food.