How does the prison cut off criminals from the outside world?

jammerbuy

Prison jammer are signal shielding devices used in prisons. Many criminals in prison custody may not repent, use some electronic devices communicate with the outside world in prison, again in order to achieve the possibility of crime, therefore the prison using signal jammer, on the one hand is to prevent the criminals commit crime again; On the other hand, it is to protect the security of prisons. The security of the prison is important, and the data information of the prison needs to be kept secret, not to be stolen, or it will cause great loss.