These are very sturdy plastic! I use them to sort my books and files, my kids books (by author, by season, by type) and learning supplies (flash cards, DVDs, writing pads, math practice books, reading & comprehension practice books), kids art supplies (card stock, construction paper, etc), and TOYS! 2 of these fit side by side perfectly into the closetmaid cube organizers so those toys that dont have very many parts dont have to take up an entire 11x11 space, only half of it.
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