This is a unique 3d printed holder for not only the hearing aids but for the batteries as well. The bottom of the holder has (8) individual compartments for storing batteries. The battery compartments will hold all (3) popular sized hearing aid batteries including size 10 (yellow), size 13 (orange), and size 312 (brown). After loading your batteries into the compartments they will be conveniently available for use. There is also a small opening at each position that allows for easy visibility of how many are available.