All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
The fatwa which we give is that it is prohibited for men to wear wristbands because they are considered to be like bracelets, which men are not allowed to wear because that constitutes imitation of women by wearing what is distinct to them, which is Islamically prohibited. Ibn ʻAbbaas, may Allah be pleased with him, said, "The Prophet, sallallaahu ‘alayhi wa sallam, cursed men who imitate women and women who imitate men." [Al-Bukhaari]
An-Nawawi said, "Our scholars (the Shaafiʻis) held that it is permissible for men to wear silver rings by consensus. As for all other silver jewelry such as bracelets ... the majority of scholars decisively stated that they are prohibited to be worn (by men). Al-Mutawalli and Al-Ghazaali said in Al-Fataawa that it is permissible ... The first view is the correct one, because this is considered imitation of women, which is prohibited."
An-Nawawi thus said that wearing a bracelet is in itself imitation of women.
Al-ʻAyni said, "Men's imitation of women is in clothing or adornment that is distinct to women such as wearing ... bracelets ... and the like which men do not normally wear ..."
Allah knows best.