PIE-FI increasing signal strength up to 10 times in selected direction, increasing modem's range up to 2.5 times without using any additional antennas, wires, connectors, pigtails. It is made for regions with weak cellular signal. Made for ultra-fast deployment of WI-FI on small areas like class, camping or few houses in village. Put USB-router inside PIE-FI case and connect it to USB-powerbank (or usb-charger) - all you need to get access to internet. Up to 10 wifi-devices (tablets, phones, notebooks etc.) can get access via one 4g-usb-router simultaneously. PIE-FI is small empty plastic case with 90 degree corner reflector inside. Body of this 0.25-0.4$ device can be produced from any plastic. Corner reflector made of foil glued to the walls from the inside. Main thing about this device - it can be delivered to regions OR handmade produced\replicated right there - only foil (or aluminium tin), cardboard sheet and clear tape (or glue) needed. Body can be 3D-printed.