This portable Cellular phone jammer can block WiFi GPS GSM 3G 4G signals. You can choose to turn some switches on or off, leaving only the signals you need to work properly and enjoy your time. Additionally, this optional handheld jammer is equipped with a cooling fan to ensure that the jammer remains in good condition even after 24 hours of continuous use.[a]https%3A%2F%2Fwww.jammermfg.com%2Fwifi-jammer.html[/a] <br>Total output power: 4W, each frequency band can be set to turn on or off the power,Interference range: up to 20m, the interference radius still depends on the signal strength in a specific area,Use battery or power adapter as power source,The battery is 4000mAh, enough to work for 1-2 hours.[a]https%3A%2F%2Fwww.jammermfg.com%2Fhandheld-8-antennas-gsm-3g-4g-cellular-phone-jammer-for-sale.html[/a]