I purchased this detector to replace one I had had for years. So far so good, it picks up most all of the cops I've seen (and some I don't!) It picks up store alarms and farm gps's...but overall good. I'd rather have it pick up everything and be cautious than not. After all this is purchased for 'safety'! So we can be aware of what's on the roadway: ambulances, farm equipment and cops!