Replacement or additional Fujifilm NP-W235 Li-Ion Battery Pack, designed for use with the Fujifilm X-T4 camera body.
It has a much 1.
5 times larger capacity than its predecessor, the NP-W126S, shooting 500 frames more per charge when in normal shooting mode, 600 in economy mode when used with VG-XT4 battery grip (that takes two additional batteries), you'll get 1,700 shots.