Make business mailing simple and efficient with this optional accessory. Print directly to various sizes of envelopes with HP LaserJet 4200, 4250, 4300, or 4350 Printers. - Your business mailing just got easy. Designed to accommodate a variety of envelopes of different sizes and thicknesses, including up to 75 Monarch to B5-sized envelopes, this optional accessory from HP lets you get the job done quickly and easily. - Automatic envelope printing lets you focus on real business needs. Make envelope printing an easy part of business productivity in your office. - Rely on award-winning HP LaserJet print quality and dependability for your business mailings. This optional automatic envelope feeder offers accurate alignment and takes the effort out of producing professional-quality printed envelopes.