Even though it’s illegal in USA to jam phones, there are still online retailers who sells it to interested buyer

One of the popular one is the brand-new product called the Palm. It scramble the signal of any incoming or outgoing cell phone call within a certain range

As with its name, it is palm sized and costs around $166. It’s main function is to shut down GSM 850-, 900-, 1800- and 1900-MHz cell phone calls within a 30-foot radius.