Biostore 4gb Usb Flash Drive Pen Fingerprint Security Fingerprint Capacity: 10 fingerprints (max.) Fingerprint Sensor: Optical CMOS Image Sensor Hardware Interface: USB 2.0 Resolution: 500DPI Memory Capacity: 1GB/2GB/ 4GB/ 8GB Minutia Size: 512-1024 bytes Gray Level: 256 levels ( Strict protection to secure personal data. Simple to learn & easy to use Driverless. Good recognition by optical CMOS sensor.