Clicky
With cameras and projectors, they're able to make a "cloaking field" around a tank. It's also possible to put the cameras and projectors on the tank itself to make it a portable mobile version, apparently.
I can see this as only being useful for surprise attacks, and an initial attack on the country. The tanks can probably still be spotted by infrared and heat vision, so it wouldn't be as useful when the enemy already knows you have them. Add to that the obvious dust clouds and stuff when firing.
Still, it could be a good way to plan out an attack, send in a small squadron of tanks and position them to attack. So long as the tracks and sound don't give it away =p