While lazing my neighbors house the other night (as one does) I noticed my Zenitco Perst-4, when moving rapidly, would appear to have a blinking frequency. A slow enough frequency that I could see it. Hard science then took place as I grabbed a DBal i2 (9003) and tried to duplicate the results. So far only Perst (Russian) lasers seem to do this. None of the American or even Chinese lasers seem to do it. Anyone know why?