aid batteries come in five sizes to accommodate the style and size of various hearing aid
models. Hearing aid batteries are labeled by number, as well as color
coded by the hearing aid industry so
they can be easily recognized when purchased. The five sizes are: 5-red, 10-yellow,
13-orange, 312-brown, and 675-blue.The sticky tab on the back of the battery
is also color-coded. Because the batteries are activated by oxygen it is
important not to remove the tab before using the battery.