Fits: 52 Series Olds SSI wheels. This is an Oldsmobile SSI center cap with a 2.5" back inside diameter. These caps feature the classic Olds Rocket logo in red over a black background and are designed to fit our 52 Series Olds SSI wheels. Please measure & inspect your wheels to ensure the proper cap fitment size on your order. Our catalog features more than just our wheels! Get the exact look you want with quality caps, trim rings & other accessories from Wheel Vintiques.