What is the ruling on men wearing a hair tie (toka) on their wrist if it represents a memory of their mother, is black and small, does not include adornment or jewelry, and is not intended to imitate women?

It is not permissible for a man to adorn himself by wearing bracelets and headbands, as this constitutes imitation of women. He must avoid that headband, and it is better for him to occupy himself with supplicating for his mother and seeking forgiveness for her.