The Lorex L17LD424251 Professional Surveillance System comes complete with an integrated H.264 250GB SATA HDD which is removable & expandable to 500GB. H.264 is the latest compression technology that stores over 30% more video than MPEG4. This all in one system observes 4 camera locations & is equipped with Internet remote software supported by FREE Lorex DDNS service to access your system from any hi-speed internet location at NO monthly charge. The system records at 120fps, which means all 4 locations can be recorded in real-time. The built-in USB port allows for quick video transfer onto a flash drive and can also be utilized for firmware upgrades. Triplex operation enables simultaneous playback & view while continuing to record locally or remotely. The system features a Graphic User Interface with included Mouse for simplified system navigation in English, Spanish or French. Includes four Indoor / Outdoor Weatherproof color day/night cameras with 40ft Night Vision. System also includes a 10 ft. Ethernet cable, PS2 Mouse, remote control, 60 ft. of BNC terminated extension cable per camera and software for remote network use. Toll Free Tech Support is available 7 days a week (except certain holidays) at 1-888-42LOREX -- Mon-Fri 8AM -11PM (Eastern Time) & weekends Noon-6PM (Eastern Time)