It’s a �20 Firewire and USB enclosure for a 5.25″ hard disk, CD writer or DVD writer.
Amazingly it comes with two different kinds of Firewire leads and a USB lead, plus a screwdriver. You don’t even get a USB lead with some printers costing 4 or 5 times as much.
I put my RevA iMac’s old hard drive in the enclosure, screwed it together, powered it up and plugged it in to the iMac’s own USB 1.0 socket – it’s running OS 10.3 – and my old iMac’s hard drive appeared on the desktop, so I can get any data off that I forgot to transfer.
It’s a bit noisy (so’s my expensive Lacie FW hard drive) and a bit ugly, but for �30 all in, who cares?!