One thing I have noticed since buying the CTX is I dig way less of the crimp type bottle caps. I do find many of the screw on style of caps however. Most likely, is due to those crimp caps having higher amounts of ferrous metals in them vs. the screw caps. The majority of the time, I know, now, what the signal is for those screw caps but I'll dig them anyway, because you just never know. My Equinox on the other hand was a magnet for those crimp style caps. Aluminum cans or can slaw, is another fun item to find but I use that trick of hovering the coil several inches above the ground and if the signal is still strong, it's probably an aluminum can or a mass of aluminum slaw.