Our HD DVR recorders use HD-TVI technology to record high-definition surveillance video (up to 1080p full HD resolution) over coax cabling. Combined with HD-TVI cameras, HD digital video recorders offer a megapixel recording solution for a lower cost than a similar IP surveillance solution. Many of our HD DVRs accept inputs from both HD-TVI and standard analog CCTV cameras. This enables you to upgrade an existing video security system to HD without replacing all of your cameras. Alibi HD-TVI DVRs also support a limited number of IP cameras for even greater surveillance flexibility.