Remote Focus Unit, sometime pronounced "arfoo." A small, handheld keypad and display allowing a user to call up channels and often run cues without being physically at the control console. Referred to as a "rigger's remote" in many non-US countries. Always wired unless preceded by "wireless" or "radio." One of the first, in the early 1980s, was by Kliegl Bros. using a Texas Instruments calculator shell and keypad. RFU for the ETC Express/Expression3 console family: http://www.etcconnect.com/Community...xpression-emphasis-remote-focus-unit-rfu.aspx The wired RFUs for the ETC Express(ion) and Obsession use the Switchcraft-style, gray-insert, "symmetrical" 6-pin XLR connectors. For pin-out and wire specifications, see the ETC wiki at http://www.etcconnect.com/community/wikis/products/rfu.aspx . The original remote for the Strand-Century LightPalette line had no display, but did have a single fader. The remote for the Colortran Prestige, Encore, and Innovator lines had a two-line LCD display, but a very annoying membrane type keypad. See also RFR and iRFR.