Sadly my goto No1 / 3mm clipper cover for (Wahl trimmers) has broken and there is no replacement available without buying a full set
This was made to be an absolute pattern fit and size to the original. If printing from STL you should print with the outer face as base. I added base support for both the hair tines and the rear clip (easy enough to remove - but I also sanded the outer face of the tines to ensure absolutely smooth on the skin).
This 3mm cover is made to fit Wahl Trimmer Model 9870L, but from what I can see the clipper guards / clipper head seem similar on multiple models
The author marked this model as their own original creation.