...aaahhh. Now we are getting somewhere, Marconi. It was this type of technology that I saw and read about. However, it was mounted on a Humvee.
On a similar subject, I have also read a little about the ceramic armour protection. Apparently it too is used as a means of defeating HEAT rounds by slightly deflecting the resultant jet of gases perpendicular to the armour. Claims are that this not only disrupts the gas jet, but also introduces more relative armour to pierce due to the deflection.
Appreciate all those who have contributed. But the slat device on the M1A1 and its purpose remains elusive.