This bearing consists of two sheets of 111 diamond that have been bent into two hoops. The smaller hoop has been inserted into the larger hoop to produce the bearing. The structure is chemically very simple. It uses only two atom types: carbon and hydrogen, and only two bond types: carbon-carbon single bonds and carbon-hydrogen bonds. A description of a bearing such as this one can be found at http://www.zyvex.com/nanotech/bearingProof.html. Devices such as this have been designed by K. Eric Drexler at the Institute of Molecular Manufacturing (www.IMM.com) in California, and by Ralph Merkle.