They are all made from mugs but some mugs have rubber grippies that protrude through the sides. When you remove the grips, the holes are left.
With these smaller stoves I have been using a continuous windscreen with no gap (for handles) that either rests on another type of clip mount or on a clip and wire stand that can be inserted in the ground. This works extremely well and is easy to add and remove while burning.
It sure is a nice added plus that the grippies have left you some tactical looking air intake holes
The windscreen with the opening allows twigs to be feed in the side port, right?

