This a very high-gain Wifi Antenna, that is also very easy and cheap to make. It is a "corner reflector" design and can be made to slip right over the rubber-ducky antenna on your router.-This is a very high-gain Wifi Antenna, that is also very easy and cheap to make.　It is a "corner reflector" design　and can be made to slip right over the rubber-ducky antenna on your router.