Prat Start Spiral Book Refill, Top-Loading Polypropylene Sheet-Protectors, Archival and Acid-Free, 11 X 17 inches, Landscape, Pack of 10 (SRL-17) Genuine Prat refill page sheets for 17X11 Landscape START series books Heavy weight polypropylene for professional presentations 100 percent acid and ligne free Package contains 10 sheets-20 sides back and front High quality and archival