Different types of jammer use range is not the same
The cell phone jammer is mainly used to shield all mobile communication signals around, such as the GSM 3G 4G signal network. Some high-performance jammers can also block the GPS WIFI UHF VHF band. At the same time, some mobile phone jammers with GPS interference function can also prevent GPS location tracking. Once the device is running, all nearby mobile phones cannot access the Internet, thus keeping the environment quiet, while preventing information leakage and stealing.  The possession of jammers is not a ban. In special circumstances, it is allowed to operate cell phone jammers. 

http://www.jammer-buy.com/cell-phone-jammer/c-24.html

In addition to normal positioning and tracking, the GPS tracker can also make two-way calls. It can answer incoming calls by setting the authorization number corresponding to the button. It can also be used for emergency alarm, overspeed alarm and burglar alarm. In addition to being used for security purposes, GPS is used for illegal activities. For example, remote monitoring will set the monitoring number. When the number is dialed to the terminal, the terminal will automatically answer the call, thus monitoring the effect.GPS trackers are used in a wide variety of applications, such as tracking for children and the elderly, road inspections, wildlife tracking, car theft, motorcycle burglary, bank cash trucks, pet tracking, private detective tools and more.

http://www.jammer-buy.com/gps-jammer/c-25.html

Due to the large traffic volume in these places and the large number of users of public WiFi, this also leads to the slow speed of the WiFi network. However, almost everyone is accustomed to link the WiFi network. The hackers formally use our WiFi network to steal the contacts and store data and passwords on our mobile phones through some technical means, which is very dangerous for our information privacy.However, almost everyone is accustomed to link the WiFi network. The hackers formally use our WiFi network to steal the contacts and store data and passwords on our mobile phones through some technical means, which is very dangerous for our information privacy.

http://www.jammer-buy.com/wifi-jammer/c-29.html