The Selker Rift was a hyperspace rift about twenty light years short of the Sachsen System.
It was essentially a volume between two prominent grav waves. It was unavoidable for starships traveling between the Anderman Empire and the Silesian Confederacy on the Triangle Route. Most ships crossed it under impeller drive at a speed of .16 c to allow them to dodge a dangerous rogue wave known as the Selker Shear. This extended the travel time through the rift to about five t-days, leaving freighters exposed to piracy.
In 1910 PD, the Battle of the Selker Rift took place in the area. (HH6)