This is a mini hidden type jamming device. It has many advantages: First of all, the design of this device is very portable. It has very small size (95mm*48mm*17mm), can be easily put into pocket or backpack. Second, the device has a very strong concealment. The device looks like a portable power source, can ensure that you are not easily perceived by others during your use. Third, although the device is very small, but it can also jamming multiple signals. Whether you need to block cell phone signals or WIFI signals or GPS signasl, this device can do it.