The GPS 18x units by Garmin are GPS antennas that connect directly to your PC via USB port. The 18x PC is a small puck style antenna, at 61mm in diameter and it is WAAS enabled. The USB cable is 7' long and will connect to a USB port on your PC obtaining power from the laptop, through the USB port. Compatible with most Garmin software products.
Product Accessories for Garmin GPS 18x USB receiver for PC Antenna Only