{{Infobox model parameter| name = {{PAGENAME}}| param = <onlyinclude>''Φ<sub>ex</sub>''<noinclude/onlyinclude> The fast | desc = Fast exchange factor, in .| equation = {{:pA}}{{:pB}}{{:deltaomega2}}| units = rad<sup>2</sup>.s<sup>-2</sup>. This is equal to:: {{:Phiex}} = {{:pA}}{{:pB}}{{:deltaomega2}}