Book jacket protector for paperbacks, the thing I didn't know I needed until my mass market copies started falling apart in my bag. Made by Corine Marie. Comes in multiple sizes so it fits mass market, trade paperback and hardcover. Clasp closure, and an inside pocket that holds my annotation page flags so I stop losing them at the bottom of my purse. If you read on the go or annotate as you read, this is the one. LTKSeasonal LTKOver40 LTKselfcare