Compatible Camera: Fits the Sony Alpha a9 II and a7R IV cameras Battery Type: Holds up to 2 NP-FZ100 batteries to double the power USB Charging: Charge batteries via camera USB without removing grip Auto Switch: Camera can automatically switch from one battery to another for continuous operation Durable Design: Lightweight, compact design matches the dust and moisture-resistant durability of the Alpha a9 II and a7R IV