The HP A2W83A is a booklet maker/finisher accessory rated for up to 3,000 sheets, designed to attach to HP's LaserJet M855 and M880 series printers. A finisher of this type takes printed sheets straight from the printer and automatically folds and saddle-stitches (staples along the fold) them into finished booklets, without requiring manual assembly — useful for producing reports, manuals, programmes or newsletters directly in-house. It's an add-on device rather than a standalone printer, and is only compatible with the specific HP printer series it's designed for, so it's intended for offices or print rooms that already own (or are buying) a compatible M855/M880 printer.