Need help with chrome lug nuts
 

Does anyone know what size lug nuts I should purchase? I have a 2001 Boxster had the 17" alloy wheels, bought a set of 18" OEM Chrome. I'm currently using the old lug nuts and want to purchase a set of chrome nuts.

I have no idea what size to buy, thread lenght, overall lenght, head lenght???

All I know is that I would like the head of the nut to be flush with the wheel, and of course have enough thread to properly secure this big wheel.

I would appreciate your input.

Oh any suggestion where to purchase

thanks