U2-75 U2 Wheel Center Cap Serial Number C-121-2 U2 Wheel Replacement Center Cap for model U2-75 OEM Replacement Center Capwith serial number C-121-2 (see back of cap to match numbers). **Note: If the numbers do not match the cap, it will not fit your wheel! Back of cap measures 7" in diameter Chrome plastic Scroll down to Product Description for further fitting help or go to our FAQ on our store site.