I'll admit, I had no idea what I was getting into when I opened up the Pacemaker. The functionality and the features of the device are astounding. The Pacemaker Pocket DJ system is a 60 GB portable turntable and mixer that allows you to store your music, beats, and mixes on the internal storage, and spin your music on the go. The Pacemaker features the ability to play two tracks side by side, allowing fading and mixing between the two tracks. Cross fading and mixing is an easy task since you can select any two tracks on the device and have one playing while the other is cued up. Whatever track is active will play through the speakers, while you can have the preview of the cued track playing through the headphones.