Features: Microwave, dishwasher and freezer safe, Durable airtight gasket seal, Modular stackable design, Easy open-and-close four-latch polypropylene lid, BPA free polypropylene container and lid
23 cups is about 5.44 liters. My rule of thumb on smaller containers is 1.25 lbs of grain per liter. That means this should hold about 6.8 lbs of base or specialty grain. It would also hold a good amount of DME.
Also: Storage Options – Base Grain, Specialty Grain and DME