Please note that the jammer takes about 30 seconds to search and scan. After that time, all mobile phone signals will be blocked. Some smartphones will still show a FAKE full bar signal. You can’t call out or call in at this time.
The signal amplifier can affect the jamming effect, especially when the power of your jammer is smaller than the amplifier. But using two or more jammers can still override the signal amplifier.
You can go for the US version.
