The 18" x 26" Dough Proofing Box gives you a sanitary, convenient place to proof all types of dough! Made of durable polypropylene, with reinforced front and side edges to maintain structure. Can be stacked on top of each other or for proper proofing and stacking, use the compatible 18" x 26" lid (sold separately). Available 3 and 6 inch depths. Can be cleaned in a low-temperature dishwasher for convenience.