This item is hard to describe in one go! So what is it?
1. It is a 2.5" IDE or SATA hard drive docking station. Any 2.5" IDE (ATA) or SATA hard drive can be connected to the Bridge Adapter and can then be accessed via USB2.0, on an Apple Mac or PC.
2. Its a multi-slot card reader. Insert just about any memory card, and you can read/copy/move your data from the memory card.
3. Its a USB2.0 hub. By connecting the Bridge Adapter to your computer, you get two extra USB ports. You can connect USB Flash drives, cameras, etc. to either of the USB2.0 ports.
So, broken down, this is a very versatile 'hub' which can connect to any of your most commonly used types of media. No installation is required and it uses the computers USB bus power. An additional 5v jack is provided in case more mains power is required (sold separately) and two USB2.0 ports may be required to run the Bridge Adapter if you have a few devices connected at once.
With this type of bus powered item, you should only run one hard drive at a time. However, low power usage devices like memory cards and USB pen drives can all be connected at once.
The bridge adapter could be used in instances where it is necessary to often change between different types of media. It saves desk clutter, from having say a USB card reader, a hard drive enclosure or two and the related cables. Plus, having all the options in one device makes perfect sense!