Ruin Scanner
From Official Barotrauma Wiki
Function
The ruin scanner serves as a Scan Alien Ruins Mission item. It can be placed anywhere, but only certain locations on a sonar are appropriate for fulfilling the mission requirements. The player is given three of them when they accept the mission, in a metal crate. They also contain a sonar that can be set to passive or active, which can also pick up the submarine turrets. They can be placed by aiming (Mouse2) and clicking on the grid that appears or pressing E. They will begin scanning, which can take some time.