GPS Jammer: GPS Signal Blocker,In Car Use GPS Jammer,Portable GPS Jammer [p4s20a]

GPS Jammers
The Global Positioning System (GPS) is the only fully functional Global Navigation Satellite System (GNSS). Utilizing a constellation of at least 24 Medium Earth Orbit satellites that transmit precise microwave signals, the system enables a GPS receiver to determine its location, speed, direction, and time.
Developed by the United States Department of Defense, GPS is officially named NAVSTAR GPS
The satellite constellation is managed by the United States Air Force 50th Space Wing. The cost of maintaining the system is approximately $750 million per year including the replacement of ageing satellites and research and development.
Following the shoot down of Korean Air Lines Flight 007 in 1983, President Ronald Reagan issued a directive making the system available for free for civilian use as a common good. Since then, GPS has become a widely used aid to navigation worldwide, and a useful tool for map-making, land surveying, commerce, and scientific uses.
The world's unique GPS jammer/blocker that can block all GPS signals including GPS L1, L2, L3, L4 and L5 bands.