How to make no mobile phone call sound in the cinema?

Nowadays, in many public places such as restaurants, theaters, and movie theaters, cell phone jammer is commonly used in order to keep quiet. Because some people do not know the rules of using mobile phones, or ignore these codes of conduct. But with jammers, even if you use your phone without restriction, you will be restricted by yourself. It is very impolite to use mobile phones to influence others in public places regardless of their feelings, so such equipment is needed to manage them.