you can buy a lot of goods at one time, and you can change them for free after the release period. JD.COM is the largest self-operated e-commerce enterprise in China. Worry-free service for stocking goods is a professional term in this enterprise, which means that you can buy a lot of goods at one time and exchange them for new ones for free after the expiration date. The company has been committed to developing online retail business, establishing self-controlled deliverable logistics infrastructure and cross-industry value chain capabilities.