Gold mountain doesn't have a forum so I thought that I would post here! Anyway it operates on 15 KHZ and I plan on using some of the Garrett Groundhog coils as optional equipment! Just got it for Christmas and so have not had time for a field test yet! Playing with it in my house it looks impressive! It is liteweight and on the notch set-up is very good on sniffing out the nickels and rings without having to dig all those pulltabs!................HAPPY HOLDIAYS........................Joe