Note：The B2 is not compatible with the S3Pro B2 is a replaceable battery pack specially designed for BOBOVR battery straps. The battery pack can be hot-swapped through magnetic attraction. The weight is only 140g, which can better balance the front and back weight of the head, making it more comfortable to wear. The 5200mah capacity allows Quest2 to achieve twice the battery life, and can be quickly replaced by multiple battery packs to achieve unlimited battery life. The maximum charging and discharging power of 15W can keep Quest2 running while maintaining power. When B2 is exhausted, it can be fully charged with 80% power in 2 hours. It has 4 power indicator lights, a halo working light, and multiple redundant safety designs.