This product has a very simple function. Attach a 9V battery and the thing will beep every once in a while. To make it difficult to find, it emits a high pitched beep that is tough to localize and will go into a sleep mode every once in a while. Then it wakes up and starts all over. If you have ever had a smoke alarm in your house beep in the middle of a night because the battery is dead, you know just how annoying this thing will be.
Product Page ($14.95)