TROY is a global technology company whose legacy of innovation and commitment to engineering excellence are reflected in an extensive line of its hardware and software solutions, designed to meet the evolving needs of Internet and Wireless Appliance Connectivity. In addition to its award-wining product line, TROY offers a complete line of printer consumables that provide outstanding results to your equipment. This toner cartridge is designed for TROY 508, 512, 512 Plus; HP LaserJet 4, 4 Plus, 4M, 4N, 5, 5M, 5N EX engine.