... with VGA, USB, network, RS485 PTZ controll, IE browse 4CH DVR H.264 compression, dvr recorder support SATA4CH, M-JPEG ... compression, support SATA HardDisk, USB*NTSC:30FPS PAL:25FPS*4ch separate video display and compression, video simultaneouslyNO Audio*Recording ... ,tour,alarm,email,snapshot & FTPAudioAudio CompressionG711ABidrectional TalkSupport 4CH DVR H.264 compression, dvr recorder support SATA