... usb dvr for 4 channels,usb dvr box,dvr, cctv dvr,mini dvr, pen recorder,video recorder,easycap3104,gum ... recorder,voice recordermini usb DVR support window 7&vista system 64bits capture High-quality video and audio file.CharacteristicSize ... Contrast, Hue and Saturation (to each camera)9. Authority control: Access control for total security operation through multi-levelpasswords10. Remote monitoring: ...