Features: 1.BOBOVR specially developed a Strap upgrade kit for Pico4, which can improve the battery life and comfort of Pico4. It includes a circular power supply system composed of 2 magnetic suction battery packs and a charging stand, and upgrades the back of the head cushion and the top Strap. 2.Using BOBOVR's innovative magnetic design, the battery pack can be quickly replaced with one hand at any time during use to keep the battery fully charged. 3.Each battery pack has a capacity of 5200mah and provides 12w discharge power 4.The magnetic charging stand does not include a USB charger, please use Quest2 or other standard USB-C chargers 5.The matching B2 battery pack weighs only 140g and has a capacity of 5200mah. It can double the battery life of the Pico4 when fully charged, and can provide unlimited power supply by changing the battery