Features: This product is only suitable for BOBOVR M1/M2 Plus series headband, it can be changed to a battery pack Strap, the old M2 is not compatible, please do not buy it by mistake. Improve battery life, this product comes with 1 BOBOVR B2 battery pack, each B2 battery pack brings about 3 hours of extra battery life, if you buy a second battery pack to use alternately, you can get unlimited power Sense of levitation design style, through the dark gray design of the Dock part, it is hidden in the shadow of other dark gray parts of the product, and only the white B2 battery pack can be seen visually. This makes its design language look more concise Upgrade to battery strapB2 battery dock is an expansion component specially designed for BOBOVR PLUS series straps. It can be fully fitted and upgraded through the expansion port reserved by the strap, and the standard strap will be upgraded to BOBOVR plus series battery strap. Magnetic hot swap, the product is designed with a magnetic connection to the battery pack, making it easier and faster to replace the battery pack and increase your battery life