You can purchase a 16" or 20" Halo Volume Bundle. It includes a Volumizer Weft which you can clip directly on top of the Halo to add additional thickness. You can also clip it in over your Halo. To learn more about the differences, click here.
The Volumizer Weft is an individual 45 gram, 4-clip weft, 7 inches in width, and 20 inches in length. It is great for adding more volume if needed or if you want to experiment with adding in a Balayage shade for added dimension to your hair color.