The first is to determine your budget. Cell phone jammers, GPS jammer, and other jammers are known to vary widely in price depending on the number of cycles used. So the more your jamming device interferes in a weekly wave, the more expensive it will be. So how much do you want to pay for this device? Once you do this correctly, you will be able to start looking for interfering devices.
Second point: we are always advised to buy any type of jammer. Then read some additional information to learn how to operate the device.
It's not difficult. It's not like rocket scientists study how mobile signals and GPS jammers work. If we take this process seriously, your phone will be a dual device and run on two different frequencies. One for receiving signals and the other for sending signals. So basically your cell phone jammer will send the same frequency at the same time, making your phone unusable. It is a device that temporarily prevents you from making or receiving calls by placing the terminal outside the service area.