Fit-Power NP-FZ100 AC Power Adapter ($38.99 from Amazon) offers continuous A/C power for Sony a9, a9 II, a7 III & a7 IV Series cameras. NP-FZ100 dummy battery kit replaces the Sony NP-FZ100 Z-series battery and allows continuous studio photography without the need to replace and recharge multiple batteries. Made by flame-retardant plastic and electronic components that offer over-voltage protection and over-current protection.