The Lorex ACC1511 is a great way to connect up to 4 Lorex surveillance cameras with a 6 pin DIN ouput to any device with a BNC connector - including DVRs or an observation system. Additionally, this 12V adapter will provide the power for all 4 cameras.
ACC1511 Power Adapter Accessory Pack (6 Pin DIN to BNC)
12V 2A Adapter
6 Pin DIN to BNC Adapter