If it's a #2 all over you'll have no problem finding the remaining patches with your hands. No mirrors needed, just feel your head. This is true for most guards

If it's a #2 all over you'll have no problem finding the remaining patches with your hands. No mirrors needed, just feel your head. This is true for most guards about #4 and below. Above that and the length of the hairs are not different enough to feel the differences.