Griffin NuuMed Everyday HiWither GP Numnah Brown. The Everyday HiWither GP Numnah is a popular lightweight numnah that is hard wearing and versatile. The HiWither Numnah is specially shaped to contour to your horse's back and is suitable for everyday and competition use. The Everyday HiWither Numnah offers a polycotton drill 5oz lightweight quilt in a high wither design. Machine washable.