Box capacity: 2 x 1.5V AA batteries(no included) Features: - Easy to install.? - Lightweight convenient to carry. - Be used as a perfect external power source. - 3 volt battery holder with on / off power switch wire lead. - You can use this case with your own battery to form power system supply. Package included: 1 x DIY Battery Holder (Batteries not included) Notes: 1. Manual measuring please allow 1 ~ 3mm error thank you. 2. Due to the difference between different monitors the picture may not reflect the actual color of the item. We guarantee the style is the same as shown in the picture.