Costco here has been selling these mosquito repelling units, appears to operate as a plastic clip on module with a battery powered little fan, and the claim is that they surround you with a cloud of repellant. The Costco units seem to be a pretty good deal with 5 refills and it also seems that you get a new fan battery in every such refill. I've only seen one of these in use, a referee at a 3 gun competition, and didn't ask him for feedback. I have to say the thing looked a little sissified in the 3 gun environment, but that's my boyhood hillbilly self talking and if these things work, I do hate coating myself in DEET. So, has anyone used the Off! thangs?