New front internal oil gallery plug.  Sits in engine block just behind front timing cover.  For all LS based engines.  Fits the following:

97-12 LS1/LS6/LS2/LS3/LS7 Corvette
98-02 LS1 Camaro
98-02 LS1 Trans Am
04-06 LS1/LS2 GTO
04-07 LS6/LS2 CTS-V