I use a Vibraprobe 560 and I am happy with it. The closer you get to your target, the more it vibrates. That's how you know you are right on top of your target. Why would anybody want a probe that detects up to 3" or more? The purpose of a pinpointer it to tell you where your find is, not "It's around here somewhere, keep on looking." Your detector should pinpoint it to within 2" or 3". In my opinion no more than 1" is fine.