These massive constructs are large enough to jump the largest ships between two linked jumpgates. Currently, there are 4 working gates, with a 5th in the works. They can jump ships up to 3 km2, although nothing that large has ever been built (the biggest ships are up to 3 km long, but length is not generally an issue. They are heavily guarded, so most pirates won't go anywhere near them. It isn't free to use the jumpgates, but they are currently the only way to go between two systems.