If the first three characters of the serial number are C4M or FL4, the cable is for use with an Apple USB-C Power Adapter up to 61W.The cable's serial number is printed on its external housing, next to the words 'Designed by Apple in California. You can verify that you're using the correct version of the Apple USB-C Charge Cable with your Mac notebook and its USB-C AC Adapter. USB-C cables rated for 29W or 30W will work with any USB-C power adapter, but won't provide enough power when connected to a power adapter that is more than 61W, such as the 96W USB-C Power Adapter. If you use a higher wattage USB-C cable, your Mac will still charge normally.
For the best charging experience, you should use the USB-C charge cable that comes with your Mac notebook.
