10 NOS 3903539 radiator support wellnuts for 1967 1968 1969 Firebird Trans Am and Camaro. These push in to the radiator support on the driver side which screws go into them. When the screws are tightened it swells the end of the nut and holds the radiator in place. Last two photos are samples of what they look like out of the bag found on the internet. You get the GM sealed bag of 10 of them inside.