Set of 4 Genuine SAAB Alloy wheel centre caps. 
 
External Diameter = 6.5" / 165mm (approx.)
Internal Diameter =  2.5" / 65mm (approx.)
 
I believe 1 of these is a NOS piece that has never been fitted.  All 4 in excellent condition with only minor surface scrathces, none of which are visible unless very close up.  I have tried to picture all blemishes as best as possible