ImageUSB is a free utility which lets you write an image concurrently to multiple USB Flash Drives. Capable of creating exact bit-level copies of USB Flash Drive (UFDs), ImageUSB is an extremely effective tool for the mass duplication of UFDs. ImageUSB can also be used to install OSFClone to a USB Drive for use with PassMark OSForensics.
Unlike other USB duplication tools, ImageUSB can preserve all unused and slack space during the cloning process, including the Master Boot Record (MBR). ImageUSB can perform flawless mass duplications of all UFD images, including bootable UFDs.