Several available, ideal for monitoring EVS, VTs, cameras etc. Realtime video processing with digital processing. Sony ys-q430 4 channel composite multiviewer in pal formatFull working order19inch rack mountable so perfect for OB trucks, studios, edit suites etc4x composite analog inputs with loop thruMain Output from unit is a quad display multiviewer output. (all 4 inputs shown on 1 screen in a quad display)2nd outputis separate and can be used to monitor 1 input or do a rotation onall outputs (Switch between each camera etc automatically or manuallyswitched.Unit has built in menu options toset time if you want, ID name for each input if you want (eg cam 1, cam2, evs 1, etc etc). or can be switched off of course.has alarm output also to warn user or loss of input etc if you want also.