John, sorry I don't get it, other than deeper in the waterproof dept. It seems like a gimmick--if you want privacy--don't want to take your headphones off, just use on vibrate which is how I run my carrot all the time. Batteries last forever it seems. Now if it could discriminate ferrous --non-ferrous that might be something. I have a TRX and a Pro-find 35, But I use the carrot on every hunt. Hearing impaired or in water it still runs on vibrate so I can't see any advantage and just something else that could go wrong. If I'm missing something PLEASE I'm all ears. JMHO HH Mark