Flash drive or flash disk is the most useful innovation in computer accessories. It won't be wrong if pen drive is given the status of best removable storage media. It started with few MB storage (16 MB) and has already reached to 256 GB or more. It is the ease of use, portability and reliability that contributed to popularity of USB flash disk. Use of USB flash disk required installation of flash drivers with Window 95/98 and Windows ME but later windows editions detect these drives as plug N Play device and do not driver installation separately. As per the claims of manufacturer's,  flash drives may allow upto 1 million erase and write cycles and can retain data safely for 10 years. Because of flash drives advent, floppy disks have become a thing of past.

There are usually two components of a flash drive: 1. printed circuit board and 2. USB connector. These USB flash drive functions using the power from the USB connection and do not require a separate power source. However, devices functioning as a digital audio player may require a battery.

USB pen drive are available in different designs in the market and price varies depending on storage capacity, housing unit and manufacturer. Some flash drives comes with a cover on USb connector and some drives have retractable USB connector.

Sony's pen drive are relatively costlier but reliable and comes with good warranty. Other known brands are:

1. Kingston
2. Transcend
3. Sandisk
4. Umax
5. Quantum
6. Imation
7. Corsair
8. OCZ ATV
9. Silicon Power
10. Verbatim
11. HP
12. Toshiba
13. IBM
    

Flash drives are available in style and housing material of leather, silk, plastic, metal, and wooden. Different designs of the USB drive like Pen, Bracelet, stick are available in the market. Flash drive are also available in the pen shape and keychain shape. These USB drives have about 8 GB storage capacity in addition to a spy nano camera hidden in the device. Youth can enjoy these drives as wristbands and carry their files with them.