FS4 is a 4-Channel 2K/HD/SD or 1-Channel 4K/UltraHD frame synchronizer and up, down, cross-converter. AJA’s flagship frame synchronizer and converter offers incredible versatility and connectivity in a sleek 1RU frame for all your 4K/UltraHD and 2K/HD/SD conversion needs. Offering a wide range of connection options for both video and audio, FS4 can do the work of four separate devices in 2K/HD/SD or combine all processors and channels together for maximum flexibility for 4K/UltraHD productivity.