Summary: Most of the time, when I turn the power switch on, the mouse doesn't get battery power. Well, in my frustration, I slapped it down on the desk, and it worked. I have to do this, smack down on the desk method every time to make it work. don't buy it...its a pos.
Summary: The purchase arrived earlier than expected. This is a great buy. I bought the same mouse several months ago at one of the well-known electronics stores & paid nearly twice as much. The mouse requires 2 aaa batteries which are supplied .