This thing works remarkably well considering it only uses two small AA batteries. Fantastic for people who have problems with their hands, also useful for those who want tins to be opened while they get on with something else!
Place tin on hard surface, place opener on tin, press button, go away and do something else. Come back a few seconds later and your tin is open...no sharp edges, no mess, perfect.
Batteries are easily replaced, the back just slides off, not that I've needed to do so after 3 months so far. I bought two of these, one for myself and one for my parents for Xmas (2007), both have performed faultlessly.