The DNF ST400 VTR/DDR Controller is a professional control surface engineered for precise, real-time operation of video tape recorders (VTRs) and digital disk recorders (DDRs) in broadcast and post-production environments. It provides a familiar, "hands-on" user interface, which helps operators transition to file-based workflows while maintaining the speed and tactile feedback of traditional tape machine control. The robust design is widely used in demanding, fast-action sports broadcasts and live production for quick, accurate replays and clip management. The ST400 can control up to eight video channels individually or ganged together and often works with software systems like DNF's Cliplist for fast access to hundreds of video clips.