Oxford C6193 Catalog Binder with Expanding Posts, 5 1/2" Cap, 11 x 8 1/2, Black Expanding binder with telescoping posts, slide-action post mechanism, a transfer bar system and metal hinges. Telescoping posts make adjusting the width of this binder a breeze; just pull the cover and you're done. Slide-action post binding mechanism keeps contents tidy. Transfer bar system allows you to add, remove or substitute paper into the front, back or in-between existing pages. Metal hinges reduce wear-and-tear on the binder.