i just dont believe in them. mainly because any radar detector ive seen being used always still got a ticket so thats just my opinion. also here in ohio they like to have speeding stings where they will have a helicopter catch you and report you to a cop thats miles away and no radar will be helping you there. i personally say go the free route and use common sense as in cops usually sit in the same spots, when a cop is around you see people breaking well in advance, and dont speed in stupid areas and youll be fine.