Portable storage device
This article needs additional citations for verification. (July 2017) (Learn how and when to remove this template message)
Some are fixed size hard drives of 256GB, 320GB, etc. Newer units are expandable using 2.5" laptop hard drives, allowing for an unlimited storage capacity, which is useful for video and images.
When travelling, a portable storage device may be a useful alternative to backing up or purging memory cards if a computer is unavailable for downloading.
Many PSDs will connect directly to a camera and copy the images, or they may provide a slot for a memory card to plug in, with or without a card reader device. Some early models allow the user to review the images on a colour screen, but at the top end of the market.