As far as I can tell these are the real deal, original Milwaukee Red Lithium 5 AH M18 batteries. They come in a blister pack and look exactly like the other 5 AH ones I already have. Mine showed up partially charged and took on a full charge fairly quickly in my charger. We'll see how well they last, but so far so good. Try 'em out.
Good general use battery with a reasonable weight. Large battery are great, but the weight makes some tools tiring to use. I find the 5ah batter to be a good weight/runtime combo.