Different types of shielding devices can be suitable for different situations. The specific effect of frequency jammers not only depends on the efficiency of the equipment itself, but also on the actual site terrain, nearby base stations, building materials, and whether there are unnecessary obstructions. For example, when signals pass through reinforced concrete, glass, and wooden boards respectively, the degree of signal attenuation varies, and to some extent, it will have some impact. In the current era of communication, there are more and more places where frequency jammers are used, such as exam halls, gas stations, conference rooms, and other places that can almost be encountered. In these places, blocking devices are used to block mobile phone signals, so that the phone does not need to be turned off and unnecessary trouble is avoided.

The frequency band used to block the signal received by the mobile phone from the base station is the working mode of the frequency jammer. In general, the power of the transmitting frequency band of the shielding device is greater than the power of the received signal of the mobile phone, in order to achieve the effect of the mobile phone signal being blocked. On the contrary, it will not have any effect, let alone affect the use of the phone. Therefore, it is important to pay more attention to this aspect when using these shielding devices. Of course, there is not much accurate data to support the effective coverage area of frequency jammers, and there are many factors that can affect it. Before choosing it, we still need to test the interference effect of the device through our mobile phone, and then make the selection based on the actual situation.