Marker Rings were rings worn by Nobles from the planet Kilia IV. Each one bore the heraldry of the noble's particular house, along with a tiny transmitter and receiver. When two marker rings from the same house would come in close contact, the transmitters would recognize each other and cause the rings to glow.
Kilian Rangers who were also nobles would have a chevron denoting their rank as Rangers emblazoned on the ring as well. A bronze chevron indicated a Squire, a silver chevron identified a Ranger, and a gold chevron denoted a Kilian Lord. Also, many Kilian Rangers with marker rings would often turn them into Force Talismans.