I have been struggling for some time to power my favorite cat clock with wagging tail and moving eyes. Ordinary alkaline batteries would last for a few days and then my favorite clock would slow down or stop altogether. Because I had to replace the batteries so often, I was starting to believe that it was an issue with the clock, rather than the batteries. Then I tried these "Fusion" batteries from Rayovac. I have to say that I am really impressed. With Rayovac Fusion batteries, my clock has been going strong for approximately a week with no signs of slowing down. I am not sure how they pack so much power in a battery, but Fusion batteries definitely set a new standard for alkaline batteries. In fact, having tried these batteries, I doubt if I will ever go back to regular alkaline! I have attached several pictures of my Rayovac Fusion batteries. Don't be deceived by their "ordinary" battery appearance, these batteries are both powerful and long lasting. I am required to mention that I did receive this product for free in exchange for my product review. However, my opinions are entirely my own.