 "GoPro Battery BacPac (Camera Not Included)" "Pedometers - Page 3 | All Fitness Gadgets"
"The Battery BacPac is a removable battery pack that seamlessly attaches to the back of your GoPro to increase battery life. Now featuring 15% more battery capacity than the previous model, it's perfect for all-day adventures, marathon surf sessions or any application where you need extended battery life. Itâ€™s also ideal for activities where charging or swapping in a fresh battery is difficult, like scuba diving and overnight backpacking. You can charge it with any standard USB charger, the GoPro Auto or Wall Charger,1 or a computer.2" 
 " GoPro Dual Battery Charger + (for HERO4 Black/HERO4 Silver) (GoPro Official Accessory) "@en-US "GoPro | Com"@en-US
"Compact Dual Battery Charger for HERO 4 batteries. Charge using any powered USB source (AC Adapter, Car Adapter, Laptop, etc.). "@en-US 
 Item Weight 0.34 pounds Item Size 4.17 x 7.09 x 7.09 inches Package Weight 0.35 pounds Package Size 4.57 x 1.97 x 1.97 inches Units in Package 1