GoPro Hero4 Black review: Smooth 4K video that's still the best in the category - CNET
Amazon.com : GoPro Rechargeable Battery for HERO4 Black/HERO4 Silver (GoPro Official Accessory) : Electronics
GoPro 2 Genuine Original Rechargeable Battery Pack for HERO4 and GoPro HERO4 Dual Battery Charger for GoPro HD Hero 4 Black Silver AHBBP-401 AHDBT-401 | Gopro, Smartphone charger, Battery pack
GoPro Hero4 Session review: Ousted by the Hero 5 Session? | Expert Reviews