the guy that sold me a unit 12 yrs ago threw down coins, nickles, and used them to set disc. he would just make sure he had the nickle. i still do that out of habit, and i find a lot of nickles. i plan on the BH505 with the 8in to try a test and see just what the factory does, and what it actually does. i read they are most accurate and seemed to be on a quick air test. i have heard they are really bang for the buck. best sleeper on market, just stay outta wet salt. i have asked around before without answer. radioshack/Bh/discovery--one had a salt mode button. it is shaped bodywise as the 505. i saw one at a pawn and went back, it was gone. i dont think i was seeing things. would love to find one with the salt mode. i checked the manual cross sites, know i saw it. any ideas? its gonna drive me nuts till i find it. see doctor tommorrow but know weeks out to hunt. tumor believed benign but nice cut! 100 degree heat no rain, gonna seperate the md'ers from the boys soon i hope. thanks carey