Packaged with longer tabs for ease of opening and ease of handling, these Duracell size 13 hearing aid batteries are colour coded to make identification simpler. The size 13 batteries are colour coded in orange. Although it is designed and manufactured to make things simple, the Duracell ZA13 battery is certainly not simple in its performance. It is in fact, strong and reliable, providing long lasting energy through the built in Duralock Power Preserve technology.