Birkin 25
The Birkin 25 is a compact Birkin size, and storage support should be matched to its usable interior rather than borrowed from a larger Birkin. An oversized insert can place unnecessary pressure on the exterior, while an undersized insert may provide little support.
For current Fabrinique sizing and storage guidance, use the Birkin Purse Pillow guide and the Birkin 25 Purse Pillow.