Based on this product's specifications, here are some alternatives and similar models
Bookend for Horizontal Roller Shutters Paperflow EO4932.02
Summary description:
Paperflow EO4932.02 is a bookend designed to fit horizontal roller shutter systems. It secures books and documents in shelving adjacent to roller shutters, providing stable lateral support. The accessory is intended for use in offices, archives and storage areas where shelving meets roller shutter openings and helps prevent items from sliding or falling.