Inside the plain white box are the three Li-ion batteries, marked as delivering 3.7v 1050mAh 3.885Wh, the dual port charger which according to the label outputs 4.2v 800mAh, a short USB to micro-USB charging cable and a warranty card.
The charger is easy enough to use. It can charge batteries singly or in pairs and shows a bright red LED for each charging port which changes to blue when the battery is fully charged.
That is pretty much all there is to say. The batteries seem good quality and last at least as those supplied with the camera and the charging period is faster than the charger supplied with the camera.
If you have a compatible camera then this is a great addition to your action camera kitbox.