Amazon.com: Skywin VR Tripod Stand HTC Vive Compatible Sensor Stand and Base Station for Vive Sensors or Oculus Rift Constellation (2-Pack) : Video Games
Amazon.com: Oculus Sensor (Includes 16Ft. Repeater Cable) : Video Games
Easiest Setup for Oculus Rift Room-scale Tracking (without drilling holes)
3 reasons why you might want a four-sensor Oculus Rift setup | Windows Central