... all 4 channels,8 channels,16 channels. 1080P*4CH HD-SDI 4CH DVR CE, UL listed HD-3104HVideo Input/Output: BNC 4CH In / 1CH ... ): 405mm×325mm×65mm, weight: 6.0kg 1080P*4CH, RS422, PTZ, Alarm, Network, 2 SATA HD, HDMI, VGA, USB Backup, USB Mouse 1080P 4CH DVR