This price is for 20 units of the batteries . You will receive 20 batteries in total (2 sheets of 10)
A watch battery, cell battery or button cell is a small single cell battery shaped as a squat cylinder typically 5 to 20 mm in diameter and 1 to 6 mm high—like a button on a garment, hence the name. Button cells are used to power small portable electronics devices such as wrist watches, pocket calculators, and hearing aids.
Manufacturers have their own part numbers for this type batteries including (they are all the same thing): AG9/SG9 LR45 194/394 6135-99-782-4675 (NSN)(S)