Native Instruments Traktor Kontrol S4 MK1. Power on, button, and fader operation confirmed. Tested with Mixxx. * Traktor Pro software is not included. * Due to the age of the model, it may not be compatible with the latest OS drivers. There are scratches and signs of use. Please check the photos. Included: ・Main unit ・USB cable Instant purchase OK. Price negotiation possible.