Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Very handy gadget

I've been cutting down a lot on my energy usage recently, and I wanted something that would help me see just how much of a difference my efforts were making, so I decided to order a kill-a-watt. When I first received it, I went around my whole house testing out gadgets to see just how much energy they use. I was quite surprised by a lot of items. I have an air purifier that stays on almost 24/7 so I was sure that it was hogging a lot of energy, however I was only using a mere 13 watts! Now I can feel comfortable about leaving it on without worrying about my energy bill.Now whenever I get a new gadget, I always test it with my kill-a-watt meter so I can set limits on how much I use that gadget. My energy bill has definitely went down since I have been using this, and I am even going to bring it to my mom's house to try to get her to change her energy-draining ways.My only complaint is that it covers both outlets. I am thinking about ordering the extender to combat this.