The root is a special part unlocked only to the Bee Faction or by using the Reassembler mod. It is used to attach stations to asteroids and other rocks. This piece is rectangular, with connectors only on its elongated sides. Both connectors are different, though. There is a smaller box indicator, and a larger point. The larger point is used to connect to the station, whereas the smaller box is used for attaching the stations to asteroids.