The bird feeder balls are not only decorative, they can also help small birds that have difficulty finding their food during the winter. The bird feeder balls are made of clear glass so you can watch the birds as they feed. Their design makes it easy for small birds to perch on the glass rim and feed. It is easy to fill the glass balls with food that can dry out, as the balls have holes in the bottom. The bird feeder balls come in a set of 2, ready to hang in the garden or on the balcony with the nylon thread provided. Matches other Eva Solo outdoor items.