Several PATH stations will soon feature a new device that could help prevent a terrorist attack. The system, Passive Millimeter Wave, will be introduced, studied and examined at various stations over the next 30 days. On Wednesday, it was being tested at the Exchange Place station in Jersey City.

Passive Millimeter Wave is similar to a video camera, except it can detect the possible presence of a bomb on a person. An indicator light on a computer monitor turns red if large amounts of energy are calculated to be coming from someone on camera. Otherwise, the light stays green.

?It has a lot of potential, it?s a lot smaller than it was when we previously tested the technology and it?s much more mobile and that?s what we?re looking for and trying to do,? PATH Director and General Manager Michael DePallo says. ?Shrink the equipment, make it more mobile, be more random.?

It is not yet known whether Passive MMW will be equipped in all transit systems in the future or who will actually pay for them.