This is a split cable for distributing audio to speakers and headphones when DJing using a smartphone or PC. The officially supported DJ apps are TRAKTOR DJ, TRAKTOR PRO, and djay. I have confirmed its operation with the iOS TRAKTOR DJ app. Regarding details such as compatible apps, I am sorry, but I am unable to provide support. I have only used it a few times, so I think it is in relatively good condition. I plan to ship it via Rakuraku Mercari's Nekopos service. Therefore, please forgive the simple packaging. - Immediate purchase is welcome. - Recycled materials may be used for packaging. - Please understand that this is a used item that has been in someone's possession, so there may be scratches or stains due to use or aging.