Make 4 holes and the mower head is unnecessary (simple and effective) 

Hello. I want to offer a simple solution for mowing with a string without a special spool coil. This option is fully functional and has certain advantages over mowing with a reel. Less weight, smaller diameter of the coil that allows you to reach inaccessible places. And the minus is that you have to manually change the string.
For an electric trimmer, I think that is exactly what is needed, since such trimmers do not have a reserve of power for working with heavy coils.
Thank you for viewing