Using a Coinstrike our area was loaded with rusty bottlecaps and they all registered as a coin..Fisher must have learned from their mistakes as ID Edge is basically a user friendly Coinstrike and had no such problems as didn't dig one rusty bottlecap...Hope this info helps someone on the forum. Nice light unit that works well and have a 6 inch coil coming to further have it (excell) in trashy areas...no pun on the Excel but its its just not an Edge....Jaclk of all trades I guess as have used a lot of Fisher units over the years...