UrQa Cubic Tablet
From Starsonata Wiki
UrQa Cubic Tablet's are used to train in the Kalthi skill KoQuii which reduces visibility by 2% per level for a total maximum of a 10% reduction in overall visibility.
They require the UrQa Cubic Tablet Blueprint to make which can be purchased from the AI station in Paxian Stronghold for 1,000,000,000 credits.
To use simply have them in your ships inventory when you go to acquire the skill and they will be traded in along with the required experience points.