Valve cover grommet, also known as a positive crankcase ventilation grommet.
Dimensions: 0.486" ID x 1.071" OD x 1.248" Thickness
Fits the following Cadillac vehicles equipped with 307/350 c.i.d Oldsmobile engines:
Brougham 1987-90
DeVille 1979-80
Eldorado 1979-80
Fleetwood 1979-80, 1986
Seville 1976-80