USB DVR 1) 4 channels vedio 2) MPEG4 video compression format. 3) 4 Ch Hi/Low Input, 1 Ch Relay Outpu professional USB DVR box with factory manufacture Mine manufacture USB DVR video capture card for many years, so we canDVR Feature: 4 channels video input in one card, the maximum display/recording rate is 25 fps under PAL format, and 30 fps under NTSC format. 4 screen display modes are available ...