Beltronics, and it saves me every day. It also makes you much more aware of how many cops are hiding in the bushes or in unmarked cars, that most folks don't recognize. I drove all night across Mississippi and Louisiana last month. It was going off a lot, I could flip on the brights and see them smokies hiding up on hills, in brush, like rock fish. I try not to speed but sometimes you have to pass or just get away from some cluster of bad drivers that seem stuck together like a bunch of retarded dung beetles.