1 Pack, 100 per pack, The BCW Resealable Book Bags are an acid free, archival quality product made of crystal clear polypropylene. These bags have a reusable adhesive tape strip on the body of the bag so the collector can fold the top flap over and lock in the book. - Resealable for your Book needs - 2inch flap for closure - 2 mil material thickness - Crystal clear - Protect Books while handling Dimensions - Size 10 x 13