Instruct: Classify the given Amazon review into its appropriate rating category
Query: Great Product - But Hold On To It Tightly

There is only one gripe that I have with Jackery that keeps it from being perfect: The thing is very hard to hold on to. I believe that the exterior finish is anodized aluminum (I'm not a materials expert - I may be wrong). It's not that the finish lacks quality; it doesn't. It is well-made. But it is extremely slick and will want to slide out of your hand. I dropped my the first day that I owned it. I contacted the company and suggested that they put rubber inserts on the sides to make the unit "sticky". I have put two wide rubber bands around mine to make it easier to keep a grip on. As far as charging goes, it is great. And that is what I bought it for. So for those emergency situations where you and your phone are away from an AC outlet or a USB jack, you've got a backup. I travel a great deal on business. Waiting in airports, electrical outlets are sometimes hard to find. Or, if you do find them, they are often crowded. The Jackery is great - just plug your phone in and you're good to go. Again, a quality product. Well-made and reliable. Just a slippery little bugger that wants to pop out of your hand.