I own one of the battery-operated (replaceable battery) models, and have been satisfied with it. I have had occasion to use it as have friends when they''ve come cruising (darn Lake Michigan weather systems), and it''s worked well. My husband and I will probably purchase another unit so we have two available should the need arise. I found one online for $90.00 at www.cabelas.com. They also advertise ginger pills and some sort of ''all natural'' oil that you ''simply rub on your skin''. Hm...wonder if it''s snake oil?
At any rate, that''s my $.02.