Maybe we all need to know that in many Chinas, there are no laws and regulations on data signal interference devices, but for our applications, we also need to know common issues, including maintenance of key parts, and where can I use them. Among the commonly used mobile phone signal shielding, it is strictly forbidden to use signal shielding to avoid phone harassment, mobile phone ringtones are prohibited, and GPS positioning system shielding protects car whereabouts, prevents tracking,…