Designed to fit Storex Letter Size Storage Trays, 3-inch deep and 5-inch deep versions. The storage trays are designed to neatly organize all your letter-sized handouts, booklets and papers. The bright colors are ideal for STEM or STEAM organization. The easy-to-grip comfort edges are perfectly sized for big and small hands. Made of nonporous plastic, the trays and lids are dishwasher safe and drop resistant. Trays sold separately. These lids are specifically designed for items 212659 & 212658.