Well, I wasn't going to comment, but RadarRoy doesn't really explain to you the whole truth on why those products work. Speed cameras are always on...therefore there is always a signal. Police officers setting on ramps, or in the median, or anywhere with there units on, are detectable. As I have stated many times when this subject comes up, there are officers, like myself, who will never patrol with the unit on, totally. Let me explain, we have a standby mode, when we truely see a speeder visually, then the thumb is quicker than your foot. Now, with that said, my signal is out there now for all to detect, but not the guy I just nailed...and, that is the only guy I wanted, so what did the detector really save? They are fine, for those areas that officers just set and leave it on, but they aren't fool proof. I will use 1 at the dragon next spring because the TN troopers have to leave theirs on because of the curves and such. But on straightaways, they could use the standby mode, and just wait for you. Jammers will not always defeat radar if the officer is good...he will get a phony reading at first, but if he is using his sound for tracking, which he should be, then he will know what is up, and nail you anyway...we are all trained to estimate speed visually in order to pass our tests for certification to operate our various units. I could also discuss VASCAR, which would blow your mind...no signal at all....just my .02