... 3G Network:EVDO( CDMA2000),WCDMAVideo Input 1/2/4 channel composite video, PAL or NTSC BNC interface,1.0Vp-p,impedance 75Ohms ... compound video, PAL or NTSC; BNC, level: 1.0Vp-p, impedance: 75Ω,Audio CompressionG.726, G711, ADPCMAudio Input1/2/4 channel ... , RCA port, liner input, Impedance:1KOhmsAudio Output1channel,RCA port, linear outputAudio talk-back input1 channel ...