Instruct: Classify Amazon reviews into positive or negative sentiment
Query: BEWARE!! VERY LIMITED USE!!

I bought this clicker hoping to use it with my Mac to go through a PowerPoint presentation at a big conference. Plugged in the USB attachment and...it would not recognize my Macbook Pro. So then I called the company and found out that this particular Kensington presenter only works with PowerPoint on a PC or Keynote on a Mac. So if you're me trying to use it with PowerPoint on a Mac, then you're totally out of luck. Was there any mention of this on the Amazon website? No. Am I angry and frustrated? Yes...VERY!!!