CHG-USB-AHDBT501 : Dual-Pocket Smart Charger for GoPro 5, 6, 7, 8 5740-13F RB-9 is 2 x AA

RB-9 is 2 x AA cells side-by-side with solder tabs

Enables operation of your ADI or REALISTIC radio from a mobile DC power source

BC-35: Desktop Rapid Chargers

The KNB-17 is a 7

NP-FS31 etc

CHG-USB-AHDBT501 : Dual-Pocket Smart Charger for GoPro 5, 6, 7, 8 5740-13F RB-9 is 2 x AACHG USB AHDBT501 : Dual Pocket Smart Charger for GoPro HD Hero 5, HD Hero 6, HD Hero 7, HD Hero 8. Accepts batteries such as AHDBT 501, AHDBT 601, AHDBT 701, AHDBT 801. Includes USB power cable for micro USB port. Charges up to 2 AHDBT 501 batteries at a time. Smart Charger, with automatic shut off when battery is full. Typical charge time = up to 2 hours. Charger unit also includes a USB Type C port, so your Type C cables can be used for charging.