PSV on board Colour Video Surveillance System Suitable for Buses and Trains. Upto 4 Cameras Expandable to 8. Simultaneous recording of all Cameras. Images can be Replayed either individually or in Multi Screen format. VCR and Multiplexer housed within a Steel lockable box. Option of either 24 or 168 hour recording. VCR has built in time, date and battery backup. Option for 4" Colour LED Monitor.