Milk crates are square or rectangular interlocking boxes that are used to transport milk and other products from dairies to retail establishments.NORTHPOWER multi-purpose milk crate provide interior storage area for the deck of boat, kayak, fishing, truck-bed, canoe, trunk storage, paddleboard, indoor and outdoor storage, garage and much more. In addition, the milk crate is also great for carrying around tools, storing books, groceries, gardening supplies and holding other household items.