Long long time ago I used Perma 15in string and button box for moving and storage all my books. They are durable and long lasting but the problem is, Perma is no longer in business. Local Office Depot/Staples stock Bankers string and button boxes too. Unfortunately, those boxes are all 24in length big boxes. If you fill in a 24in big box with books, it is very hard for you to lift and move without Dolley -- they are simply too heavy.Bankers box 0002501 is almost identical to Perma box, they are in the right size. One flat pack comes with 4 Bankers box. Must have for moving!Love this size of bankers box. I don't like the regular as they get too heavy. Plus this way you can read the front of the box while it is on shelving instead of having to store lengthwise like the other boxes. The price is awesome too. I started with one office store and it was $100 for four boxes, then checked another and it was $40.00 and then Amazon was $20.00. Amazon rocks!Got these to donate to a local non-profit for their older files. Really good price.Best banker boxes. Like the locking lid. Heavy cardboard. Not too big to carry.Easiest to assemble. Easy to carry and plenty of space to identify contents. I would order this product again for myself.