Stepping disk

Stepping Disks are a fictional teleportation technology from the Known Space universe created by Larry Niven. They were invented by the Pierson's Puppeteers, and thair existence is not generally known to other races until the events of The Ringworld Engineers.

The stepping disks are an outgrowth and improvement of the transfer booth technology used by humans and other Known Space races. Unlike the booths, the disks do not require an enclosed chamber, and somehow can differentiate between solid masses and air, for example. They also have a far greater range than transfer booths, extending several AU's (equivalent to Earth's orbit).