Headset Cartridge Bearing Enduro ACB 4545 1125 BO 1-1/8" 30.5x41.8x8 mm IS42 Campagnolo Hiddenset Standard 45° Inner/45° Outer Black Oxide

If you are not sure what headset standard your bicycle has, please reference this guide:
https://www.parktool.com/en-us/blog/repair-help/headset-standards

Not all IS42 headset bearings are created equal.  Some have 2 45° angles while others have a 36° inner and 45° outer.  Some are 8 mm thick while others are 6.5 mm thick.  Measure your old bearing carefully.