This product is relying on the good name of Duracell to give confidence to buyers who may see these Procell batteries as a good buy at a lesser price. I have purchased AA & AAA size and found that they seemed to fail sooner than I would have expected from the Duracell brand. A set of 4 branded "copper tops" will maintain the station tuning menu in my radio for up to a year. Alas,a set of 4 Procell could only manage about 4 months. And when I put a volt meter on those left in the box waiting to be used, I found variations in the output that I would not normally expect in the same batch. Quality control is lacking and letting the Pink Bunny down!