The batteries that I purchased and received appear to be genuine Duracell batteries in every way. Moreover, they were tested under load using a ZTS model MBT-1 Pulse Load Battery Tester and showed 100% capacity. This type of test is superior to just using a voltage meter because the voltage decay rate falls off greater at the end of the useful life. The Best by date on the batteries I received were 2029 (this being 2019). Duracell generally guarantees these batteries to have a 10 year shelf life. I have purchased similar batteries in brick and mortar stores with less than 10 years shown from the year of purchase. Many manufacturers expect the shelf life and the best by date to represent a battery with at least 80% capacity from when it was new. Of course storage conditions, especially temperature, can have a profound effect on this. The child resistant packaging made it a little tougher to get the batteries out of the pack, but not a big deal. There was a sticker on the negative side that needed to be removed. I am pleased with this particular purchase and, as long as I receive similar products, would buy again and again.