This is the most commonly used form of carbon nanotubes. It forms a single layer cylinder. Most SWCNTs have a diameter of close to 1 nanometer, and can be many millions times longer. Due to their electrical properties single-walled carbon nanotubes are most likely candidates for miniaturizing electronics. One useful application of SWCNTs is in the development of the first intermolecular Field Effect Transistors (FET). The first intermolecular logic gate using SWCNT FETs was made in 2001.