This Kaytee super finch sock with Nyjer seed is an instant feeder filled with our Kaytee Ultra Wild Finch Blend. It is a blend of four select ingredients, developed to call on the birds' sense of sight, which they naturally use to find their food. Perfect for finches, siskins and other small birds that prefer feeding from soft mesh socks. Wild finches prefer the straight replacement socks, over tube feeders, hands down. Soft mesh allows the birds to get at the seed easily and comfortably.