New GM fuel rail cover grommet.  This rubber grommet slides into the fuel rail cover, which snaps onto the metal valve cover stud.  Grommet fits any of the 2 positions in either cover.  Grommets are sold individually.  Fits the following:

05-06 LS2 GTO covers only

NOTE : These DO NOT fit 2004 GTO covers, nor any other GM fuel rail cover, and ONLY fits the applications we list.