a4 portable scanner:
1. the quantity of scans varies depending on the content complexity
2.600dpi high resolution,best price

a4 portable scanner:Functions (how to scan): Hold the document firmly by one hand Place the scanner on the start-scanning position Hold the scanner tight and press the scan button once Slide the scanner slowly and keep your hand stable to get the best quality picture Press the scan button again to stop scanningSystem specifications: Image sensor: A4 color contact image sensor Number of sensor: 5,136 dots (1 to 5,104 dots available) Resolution: Low resolution: 300 x 300dpi (default) High-resolution: 600 x 600dpiMaximum scanning speed for A4 size document: Color high-resolution: 13 seconds Mono high-resolution: 6.0 seconds Color low-resolution: 3.0 seconds Mono low-resolution: 2.0 secondsCapacity (based on 1GB micro SD card, scan A4 size file, the quantity of scans varies depending on the content complexity): 600dpi color: 220 photos (minimum) 600dpi mono: 290 photos (minimum) 300dpi color: 780 photos (minimum) 300dpi mono: 1,280 photos (minimum)Scan width: 8.27-inch Scan length: 300dpi: 50 inches (maximum) 600dpi: 25 inches (maximum)File format: JPEG LCD: scanning status display Auto power-off: 3 minutes USB port: USB2.0 high-speed External memory: micro SD card Standard battery: 2 x AA alkaline batteries Computer system minimum requirement Operating systems: Microsoft's Windows 7/Vista/XP and Apple's Mac OS 10.4 or above (direct plug-in, driver installation not required) CPU: Pentium or above RAM: 64MB Interface: USB portAccessories: USB cable x 1 CD driver x 1 Carrying bag x 1 User's manual x 1