Basically, it is a motorised storage carousel for CDs and DVDs which can be accessed either manually or, better, via the excellent database software which can be installed on PC. This uses a USB connector from DC-300 to PC.
Having once used one, I can't envisage being without, especially when you have a lot of disks to keep track of.
More details HERE.
This item, whilst not new, is in perfect cosmetic and working order.
I understand that they are quite difficult to acquire and when new retail at around the Ã‚Â£100 mark. Certainly, I paid that sort of money when I bought mine from Amazon.
I'd like Ã‚Â£45 for it, to include USB cable, PSU, software. Delivery at buyer's cost or can be collected.