Probably most all units actually. But, I guess what I left out was ears need to be trained over several hours in the field. The C$ gives a "hollow" sound on junk, (hard to describe) and a real crisp, solid sound on coins. There's a distinct difference that one's ears pick up on after encountering lots of different targets. This is why it's often been said that detectors like the C$ you need at least 30 hours in the field to begin to really "get it". Also, when I get a new detector, I like to dig almost everything to begin to see if certain patterns arise in the numbers or tones & what junk & coins sound like. I dug a ton of iron when I first got a C$. I don't get frustrated, I wanna know why that bent nail or cap read that way as it's part of the learning process. You learn little tricks with trash targets so you don't make that mistake again. Maybe a faster sweep, or sweeping from the opposite direction causes numbers to drop? "Try 'em all" types never get a chance to even get close to the ear training stage by trying the complex & quirky Coinstrike (or any high end TID unit) for a couple hours........