U2-45 U2 Wheel Center Cap Serial Number C-053 OR S508-45 U2 Wheel Replacement Center Cap for model U2-45 OEM Wheel Replacement Center Cap with serial number C-053 OR S508-45 (see back of cap to match number). **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.