The Otter Butter Fly Line Dressing is a Hand-crafted tenkara fly line dressing for furled, braided and silk leaders and all tenkara lines. Can even be used with modern synthetic fly lines. Leaves a thin, hard coating on your line that reduces friction and waterproofs. Won’t pick up grit like other line dressings. You can even use this on your Sakasa Kebari tenkara flies and other fly patterns. Made in the USA.