I use a V1 system here in the States that picks up most bands; K, micro, and also laser (though if you're picking up laser you're usually screwed 'cos it's already pointing at you).Thanks, Dave
One other item about "Detectors" in the US: In jurisdictions where they are illegal, the "Authorities" also have a device called a "VG2". This is a detector that finds radar detectors. On the subject of "Circles on the windscreen", you could of course be using a GPS (if you have one).