flir digimerge m4200 series mpx megapixel over coax series dvrs, 2 hdd slots, works with lorex and flir 1080p and less cameras (4 channel 2tb hdd)FLIR's M4200 Series DVRs use the latest HD-CVI technology, giving you the flexibility to upgrade your security systems to 1080P HD resolution using existing coax cabling. With support for both HD resolution MPX cameras plus standard analog cameras, the DVR is ideal for retrofit applications. MPX also facilitates advanced features previously unavailable over a coax cable including duplex transmission for PTZ control, audio transmission, and extended distance cable runs up to 2300 ft (700m) @ 720p or up to 2000 ft (610m) @ 1080p, depending on the type of cable used.*