BookFactory Carbonless Lab Notebook (Scientific Ruled Format), 25 Sets of Pages - 50 Sheets Total - Duplicator [Wire-O Bound] (LAB-025-WTR-D) Durable translucent cover Wire-O Bound Carbonless Duplicate Laboratory Notebook Wire-O binding  book lies flat when open Page Dimensions: 8.5" X 11" - 1/4" (6 mm) ruled format Each copy set consists of 2 fully formatted pages :- an original, numbered permanent record and - an identically numbered perforated carbonless transfer page with "Duplicate" watermark