The reason is that there are too many people buying and not enough inventory. Note: Many of Xiaomi's products will be out of stock at first and cannot be purchased, and will be better later. Supplement: The Mi plugboard is a plugboard released by Xiaomi on March 31, 2015. Xiaomi jack board is only the size of a pencil case, equipped with 3 sets of national standard jack and 3 standard USB (total current 3.1A, single-port support 2A fast charge), providing 110V-240V full voltage, jack board and night indicator.