4-6 oz. Tannery Run (TR) Indian (Alum) Tanned cow. Extra tough, great for boot laces, saddle strings and gear requiring extreme durability. Great length! The picture shown here is a double back...a single back would be half of this double back cut lengthwise down the spine. Priced by the square foot, but sold as a whole piece averaging 18-19 sf. Item # 123-46.