Book keepers are molded plastic strips with an 1/8'' wide verticle slot and holes for notebook rings. The 11'' keeper will accomadate standard sized books and is drilled for a 3-ring binder. Organize all your books and save!
I have used these for many years and they're great. If you like to save magazines etc., this is the product to get. Saves tons of space and helps you to organize by subject matter.
I've used these for years, and they are an indispensable item for this crocheter. I just slide it into the center of my crochet magazine and voila' it fits into my binder(and boy! do I have binders!). Some are over ten years old, but they're a sturdy, clear plastic with a solid feel, and don't show any wear.