T644N MONO LASER PRINTER 20G0350. Lexmark T644N Mono Laser Printer- The Fast Ethernet-ready Lexmark T644n provides outstanding value with a standard 514 MHz processor- 128MB memory and 600-sheet input. With its optional wireless- security-minded options and special applications and paper handling features- the Lexmark T644 is easily adapted to a workgroup s needs. Its print speed of up to 50 ppm on letter-size paper- a time to first page as fast as 8.5 seconds- and 250-000-page duty cycle make this a great workgroup solution.