A first of its kind from Urbanears, Slussen is the most powerful after-party weapon known to man. This package contains the hardware, and the free app is available for download in the App Store. To unleash Slussen, plug the adapter into your iPhone. Then connect your headphones and sound system to the adapter.Launch the app and transform Slussen into a pocket-sized DJ kit. With its pre-listening feature, you can ensure that the tunes are always bumping, even while preparing your next track. So you can blow the party up instead of out.