This is so crazy... I read your post and said, Dam... I just found one.. but last week I was at work... my son is in band in 9Th grade New Kent...they had practice for a few hours before competition later that day... Just before I got off work around 930 a.m. I was called by my wife. Requesting my help with my F75,,, She knew I wanted to spend some time hunting this day but at a high school... Well I went and with a little help for the flute player ... we retraced the path in which she thought she last had the item of question... I had her get one from another instrument so I could get some readings... It hit about a dime... 70ish.. I knew it was at the surface.. so with the F75 I went fast... soon I had it . And was she ever happy ... It is the toner knob for the instrument. from a sharp sound to a flatter one...Or something like that... This is the third time that I did a good deed... First was a wedding band for the neighbor near his fresh garden. second was a diamond gold ring near a front door under a power line...Couldn't use the F75 but the neighbor owns a 1266xb.. which after 20 yrs of trash I found the ring... BY The way.... The 1266xb is for sale...