Product Name: YZY 2019 OG Unreleased Stem Player by Teenage Engineering Demo Video: https://www.youtube.com/shorts/19OfQzrqUKM User Guide: https://www.reddit.com/r/teenageengineering/comments/192aipo/teenage_engineering_stem_player_user_guide/ This product is a prototype device created in 2019 as a collaboration between Teenage Engineering and Kanye West, allowing for the split playback and manipulation of stem audio. It is believed that only a very small number were manufactured, and there is no confirmed record of it being sold to the general public by either Teenage Engineering or Kanye West, making it an extremely rare, unreleased model. The album "Jesus Is King," released in 2019, has its song stems pre-loaded. Main Functions (as far as can be confirmed): ・Play/Pause ・Fast Forward/Rewind ・Volume adjustment and mute for each stem (track) ・Playback speed adjustment ・Looper function ・Built-in speaker ・Headphone output ・Effect processing for each track (Filter, Chorus, Delay, Distortion, Gate, etc.) 【Other Functions】 Bluetooth connection MIDI sync ※Bluetooth connection has been confirmed with my speaker (OB-4), but connection to other devices and MIDI sync are unknown. Please understand that due to the nature of this being a prototype, no operational guarantee can be provided. 【Regarding Firmware】 The current official firmware does not have the ability to add songs or record. Research on custom firmware by enthusiasts seems to be ongoing, but it is subject to change, and no future feature additions are guaranteed at this time. 【Condition & Accessories】 ・Main unit (Only tested a few times. There are no noticeable scratches, but please refrain from bidding if you are extremely concerned about the condition) ・USB-C cable (unused) 【Shipping】 Due to the New Year's holiday, shipping will be after January 4th. Please be aware of this.