The Rayovac size 13 pack of 16 hearing aid batteries purport to last longer than other brands, and this certainly appears to be true. The first one I used lasted about 20 days. They come with the guarantee that if this is not the case, then you are entitled to ask for your money back. The packaging allows for easy access, especially important for the elderly who do not want to have to fiddle with "hard to access" batteries. The packaging also fits conveniently into a pocket or a purse.
This is a mercury-free product. Not only is this a benefit as far as the environment is concerned, it does not detract from the performance as far as the hearing aid itself is concerned. It can be disposed of with normal household waste safe in the knowledge that no mercury is impacting the environment.
I would definitely recommend this product based on price, convenience, and durability. [This review was collected as part of a promotion.]