A fun bag when you want to go light weight, under arm or messenger style. It holds more than one would imagine. I like to carry a Berlingot inside my Birkin 40 cm when I travel. Then I can use it when I don't want to be weighted down with the Birkin. I put my wallet, cell phone, glasses case and make up in the Berlingot, put the Berlingot in the sleepy bag and then put it inside My Birkin. Still plenty of room in the Birkin for Ipod, book, sweater.