Protect your most treasured photographs with a museum quality archival, acid free box. This Black Lineco Infinity photo organizing box comes with sturdy metal corners and is both acid & lignin-free. Made of calcium carbonate buffered board to neutralize airborne pollutants. Holds up to 1,000 3-1/2"x5" or 4"x6" photos with envelopes or 5"x7" without envelopes. Built-in metal corners for stacking strength. Includes 12 acid-free envelopes. Additional Photo File Envelopes sold separately. Cover is completely removable. Overall Size: 7-5/8"W x 5-1/2"H x 10-3/4" Long. PAT passed, archival quality, acid free, photo safe.