This is a good product, fits my hearing aid the same as the batteries from a big box store and the price is cheaper. The reason I buy from this site is the price and service.
Private-label batteries from the well-known Clinic typically lasted three days, but with changes in suppliers, battery life diminished. Some lasted only 15 minutes, and none more than a day. After several boxes of batteries (10 cards per box) with no improvement, I tried Ray-O-Vac direct order. The product has been excellent, with full five-day battery life. Higher cost per battery, but much lower actual use cost. The Clinic could offer batteries for free, but I'll stay with Ray-O-Vac.