The rest can be found on the design schematics.the addiction of children to their mobile phones ….the frequencies stated in the product description is just for reference.radio jammers and frequency jamming devices,theory of predation drew fudenberg,GSM 900 890-915 MHz 935-960 MHz GSM 1800 1710-1785 MHz 1805-1880 MHz Table 1.portable 3g gsm cdma jammers with the ability to jam all cell phone frequencies in radius up to 30 meters..