The XR-115 was a sensor device housed within the sensor dome of certain Standard Transport Class Vessels. The XR-115 was specifically designed to detect and locate Husnock life.
The prototype XR-115 was installed onboard the SS Husnock in Season 90. During the War, several other models were installed in other vessels of the Army and Navy space fleets.
After the close of the War, the XR-115 as upgraded and re-installed on the SS Husnock just prior to that vessel's deployment on the Mission. The XR-115 was deemed highly effective at locating Husnock life even at extreme ranges.
The XR-115 operated with a characteristic humming noise, described by some as a "death ray noise". The humming and droning of the sensor would increase in intensity the closer to Husnock life the sensors drew. Once Husnock lifeforms had been locked to a specific location, the sensor would emit a mechanical "cranking" sound which was audible through the main sensor panels onboard a ship's bridge.