Designed for the standard fischertechnik storage system boxes (Sortierwanne https://ft-datenbank.de/ft-article/652?highlight=Sortierwanne ). For compartments of 1, 2, or 3 rows and lengths of 1/4 (x 25), 1/3 (x 33), 1/2 (x 50), 2/3 (x 66), and 1/1 (x 100) row.