A mix of spruce and pine wood chips ranging from 1-3" in size. Two different sizes are available (small and large). One small bag is suitable for including in a nest box for chickadees. One large bag is suitable for kestrel and small waterfowl nest boxes. Two large bags are recommended for the common merganser nest box while four large bags are recommended for the barred owl nest box. Large bags are $2.00/bag.