According to this, the director of the larger Suzhou Middle School Office missed Miss Li and answered that the school installed cell phone signal shielding devices for classrooms on weekends, including three at most. “The blocker can only be opened during the test to prevent The phenomenon of individual students" subconsciously, the organization of test norms guarantees its objectivity and fairness. "She said that the school does not encourage students to wear mobile phones in principle, and also stipulates that mobile phones should not be used in classrooms and courses.

https://www.jammer-shop.com/

As far as radiation issues are concerned, school facilities are annoyingly open bidding, and the purchased products have passed national quality inspections and met safety standards. The scope of influence is limited to the dormitory area and does not affect surrounding residents. Also mentioned the radiation test, the results showed that the radiation is very low and does not affect health. The region has studied the possibility of buying jammers because it is struggling with inappropriate cell phone users.
https://www.jammer-shop.com/cell-phone-jammers.html