Had 30 minutes to detect with my Detech Chaser using Coin program, 12 x 10 coil. Went to a local park, found lots of bottle caps showed 45 on the meter. In the bark chip area another 45, was tempted to leave it, but dug anyway and found an ankh (Egyptian symbol). No marking on back, no doubt made of pot metal. This park occupies one city block, dates from around 1925, is surrounded by power lines. Some EMI when set gain to high, no problem at low.