The ADC Diagnostix 5160N 2.5V Pocket Battery Handle features a "AA" battery handle with an on/off power switch integrated into the pocket clip. The ADC Diagnostix 5160N 2.5V Pocket Battery Handle can be attached to power the ADC Diagnostix 5140N 2.5V Pocket Ophthalmoscope Head or the ADC Diagnostix 5120N 2.5V Pocket Otoscope Head and is available in six different colors.