These are d size alkaline battery. They aren’t name brand.I always have my doubts about things that are not name brand. They so far have lasted just as long as the other batteries I have in a flashlight that takes three battery. They fit perfectly, and they have no visible flaws in the outer layer of the battery, which I’ve seen quite often on cheaper brands. So far, I’m very happy with these and look forward to the cost savings when purchasing replacements in other sizes.