EAS-4 Strut Connector
From Kerbal Space Program Wiki
The EAS-4 Strut Connector is a part that allows linking two parts together, for greater structural stability. It will be released on the 0.9 update.
Strut Connectors are currently the only part that requires a second step for placement on the ship. After placing one end of the strut, it is necessary to click somewhere else to place the other end. Once both ends are in place, the strut is created. When on the second step, clicking the right mouse button will cancel placement.
