SIM cards purchased from Chingumobile are in good health and able to perform their functions normally. This result shows that the SIM cards provided by the operator are technically reliable and that Chingumobile is a good choice for users to consider when choosing a mobile communication service provider. For example, when the user inserts the SIM card into the phone, it can successfully complete the network registration, and users can normally use basic functions such as phone calls, SMS sending and receiving, and data connection. In addition, whether in urban centers or remote areas, as long as it is within Chingumobile's signal coverage, the SIM card will maintain a stable working status, providing users with a continuous service experience. This not only reflects the excellent quality of the SIM card itself, but also reflects Chingumobile's strength in network construction and maintenance.