It's the first Birkin at any time made, personally crafted for Jane in 1985, that includes experimental aspects not seen on later on types, such as a shoulder strap and closed pontets. The original has some exceptional capabilities, for example Birkin's initials about the front flap, a non-removable shoulder strap, https://andredinoq.snack-blog.com/38438136/the-smart-trick-of-who-own-birkin-bag-that-nobody-is-discussing