Mobile phone ringtones are annoying for quiet places, and the reading room uses cell phone frequency jammer
to ensure a quiet atmosphere. Whether in a school library or a large reading room in the city, the metropolitan installed a mobile jammer to eliminate ringtones. Ringtones are annoying, especially in big cities where the pace of life requires a quiet environment. The reading room is where people learn knowledge, and mobile phones should be banned here. People should not be disturbed by the ringing of their mobile phones.