Our 4 channel color duplex multiplexer allows 4 image sources on one screen, while recording full screen images on a VCR. It has an array of features. You have the option to view full or mutli-screen pictures with adjustable dwell time and the option to view full or multi-screen pictures during VCR playback. It is uniquely programmable for recording between 2 - 999 hours. It conveniently has a built-in time and date generator with an 8 character camera title function. The video loss alert and alarm detection are structured as two distinct sounds that feature an up to 100 record. The best thing about our 4 channel duplex multiplexer is it is compatible with all standard and time lapse VCRs. There is also a 4 channel B/W (RMX-4B), 9 channel color (RMX-9CD), and 16 channel color (RMX-16CD) version available.