HP LaserJet Pro 400 color Printer M451nw, LaserJet. Maximum resolution: 600 x 600 DPI, Duplex printing: Optional, Print technology: Laser. Print speed (black, normal quality, A4/US Letter): 21 ppm, Print speed (colour, normal quality, A4/US Letter): 21 ppm, Time to first page (black, normal): 17 s. Internal memory: 128 MB, Maximum internal memory: 284 MB. Processor clock speed: 600 MHz. Standard input capacity: 250 sheets, Maximum input capacity: 550 sheets, Multi-Purpose Tray capacity: 50 sheets