HP ScanJet Pro 3500 f1 (L2741A) Duplex 1200 dpi x 1200 dpi USB color Flatbed scanner Image Sensor: CMOS CIS (Contact Image Sensor) Light Source: Light Emitting Diode (LED) Duplex Scanning: Yes Scanning Speed: Up to 25 ppm / 50 ipm (300 dpi) Resolutions, Optical: Up to 600 dpi (color and mono, ADF) Up to 1200 dpi (color and mono, flatbed) Resolutions, Hardware: Up to 600 x 600 dpi (color and mono, ADF) Up to 1200 x 1200 dpi (color and mono, flatbed) Color Depth: 24bit Max. Document Size: 8.5 x 122