3U or 3-U may refer to: * Sichuan Airlines's IATA code *A type of

Rack unit A rack unit (abbreviated U or RU) is a unit of measure defined as . It is most frequently used as a measurement of the overall height of 19-inch and 23-inch rack frames, as well as the height of equipment that mounts in these frames, whereby th ...

* Zerstörergeschwader 26, from its historic ''Geschwaderkennung'' code with the Luftwaffe in World War II *A CubeSat measuring 30×10×10 cm *The acronym for the third (3rd) catalog of Uhuru x-ray sources

See also