The BG-R10 is a multi-power battery grip designed for the Canon EOS R5, R5C, R6, and R6 Mark II mirrorless cameras, offering extended shooting time by holding up to two LP-E6NH batteries, improving handling for vertical shooting, and providing duplicate controls like shutter, main dial, and AE lock for seamless operation in both orientations, plus a 1/4" tripod mount. It's a popular accessory for portrait photography and long shoots.