Function Overview:Preview, Recording, Playback, Network, Locating System OS:Linux 3.0.8 System Control Mode:Easy Check, CP4, mouse, network (3G/4G/WIFI) Video Input:4 channels WD1+1 channel 720P Video Output:1 channel Total Resource:(4x25)FPS WD1@PAL/(4x30)FPS WD1@NTSC +30FPS 720P Video Signal Standard:Electrical level: 1Vpp/Impedance: 75Ω NTSC/PAL Optional Audio Input:5channels (1 channel IPC audio input) Audio Output:1channel Audio Signal Standard:Electrical level: 2Vpp Input impedance: 4.7kΩ Display Split:1/4/9 OSD:GPS information, alarm, vehicle No.,speed, date/time Operation Interface:Semi-transparent GUI Recording Video/Audio Compression:Video: H.264/Audio: ADPCM, G.711A G.711U