I just prefer using round coils over oval ones. I mostly use the small 5" on my G2 and have had outstanding results with it. My deepest coin has been a measure 8" quarter which came out a green color. On our last outing my hunting partner used his 5"x10" oval and I used the 5". He found 38 quarters, I found 42. He found 12 dimes, I found 28. Pennies were about the same. Just wondering if there is a 8" round coil that will work on the G2. thanks