The MuRata SR731SW silver oxide battery is a micro-sized power source for use in portable electronic devices, such as a watch. This non-rechargeable coin cell, also known as battery size 329, offers an impressive 39mAh capacity for long-lasting, continuous power. The MuRata SR731SW silver oxide battery measures just 7.9 mm in diameter and can, therefore, be used in a variety of small electronics. Please note that this non-rechargeable coin cell is sold individually. When placing an order, one unit ordered is equal to one battery. When purchasing in larger quantities, the silver oxide battery will be packaged in tear strips of five.