How loud is the device? Must not have been too bad if you didn't notice it?

Any idea what the cost was for it (and refills)?

wonder if it also works for the black flies

I was thinking about trying one of these things out.  We're going in at Lake One on Friday (6/5).  Based on your positive review, I'm definitely going to try to get one.  Hope Wally World has them, need to get some batteries for the trip today anyway.

Will post results when I get back.  Thanks for the info!

Got to test this OFF clip on dealie this past weekend on Lake 3.  To sum up - would buy again and recommend this device to others.  Does work pretty dang good I think.

Couple points to note:
Weather while we were there was much colder than normal (low 60s tops and high 30s-low 40s at night).  This certainly had an impact on the bugs overall.  Still, during the day there were bugs out for sure - skeeters and those little black flies everyone complains about.

Also - I grew up in MN and have spent TONS of time up in the north woods.  My folks live on a lake about 90 miles SW of Ely.  I'm pretty tolerant of bugs and only use deet when I absolutely can't stand it any longer.  I just don't like the stuff and use it only as a last resort.

That said, the bugs on our trip were not bad enough for me to use any deet.  They were moderate in my opinion and without the clip-on I would have just put up with them.  The other members of my party were constantly applying spray during the day.

So - 3 days in the BWCA in June, using the clip-on and no deet whatsoever - I did not get one single bite that I'm aware of.

Works best when you're stationary.  I did try it clipped on my shirt pocket while walking around.  Doesn't work too well when you're moving about.  So I used it while sitting in my camp chair and when I was in the hammock.  Takes it about 10 minutes or so to clear the bugs away.  It's not instant.  And works best when the wind is still.  Still does work when there's a bit of a breeze though.  And when the wind did pick up enough to reduce the effectiveness, it was such that the bugs were blown away anyway.

The package claims that one chemical insert lasts 12 hours.  I expected that this meant 12 hours from the moment the package was opened whether the device was in use or not.  NOT TRUE.  I used a single insert off and on for the entire trip.  There's a little window that displays the amount of chemical left I I barely used a third of the stuff.  I'm not sure how long I had it turned on all together, but it seems to me like over the 3 days I used it 12 hours or more.  The inserts really do last a long time, at least as long as the packaging claims, if not longer.

The only CON I can think of is that it does have a battery operated fan.  It does come with batteries (2 AA) and those lasted the whole trip too with no signs of slowing down.  I have no idea how long the batteries last.  Mine are still going strong.  The fan makes a subtle, though annoying little whine.  If you're the type of person who really appreciates the quiet of nature while you're out, you might not like the fan.  It didn't really bother me though.  And I became used to it after a day of intermittent use.

There is no odor whatsoever that I could tell.  I would even hold it right up to my nose with the fan blowing right at me and I couldn't detect any odor.

There were times when we were all sitting at camp and I could see the bugs around the others with no bugs within a few feet of me.  It got to the point where there were times when others would come stand next to me with the device running in order to escape the bugs for a bit.

It does work at least somewhat for those little black flies.  I did notice flies moreso than mosquitos.  Though I don't know if this is because there just more flies than skeeters in general or what.  Bottom line is that there is a noticeable degree of effectiveness for both flies and skeeters.

Like I said, works pretty much as advertised.  The inserts seem a little expensive at first, but now that I've seen how long one insert lasts, they seem like a bargain now.