Amazon.com : SOONSUN Frame Mount Extension for GoPro Hero 4 3+ 3 with Screen/Battery Extension - Use with LCD BacPac or Battery Extension - Includes Quick Release Buckle and Thumb Screw : Electronics
GoPro Expanded Battery BacPac
Amazon.com : GoPro Rechargeable Battery for HERO4 Black/HERO4 Silver (GoPro Official Accessory) : Electronics
Amazon.com : SOONSUN Frame Mount Extension for GoPro Hero 4 3+ 3 with Screen/Battery Extension - Use with LCD BacPac or Battery Extension - Includes Quick Release Buckle and Thumb Screw : Electronics
Gopro HD Hero Hero2 Camera BATTERY BACPAC EXTENDED POWER PACK ABPAK-001-R | eBay