 "GoPro Hero3 Wrist Housing - AHDWH-301"
 "GoPro Dual - battery charger USB" " GoPro USB AHBBP301 Digital Camera Accessories CDWG.com
"Conveniently charge two GoPro Li-ion batteries simultaneously with the dual battery charger. Featuring USB compatibility, you can power it with most standard USB chargers, the GoPro wall or auto charger or a computer. Dual LED indicator lights display the charging status of both batteries: in process (amber) and fully charged (green)." 