This is the original 4 deck Traktor Controller for Traktor Pro. Drivers are still available and it is still used regularly. I'm upgrading to another Traktor controller, so I'm keeping the software, which is $99 and has been as low as $49 on sale.
Ask me any questions or have a look online. There are lots of reviews. I bought this used 2 years ago without the software, with a case, for $400.