Snap Button 5mm Black From the description: Easy-to-sew center hole The thread is curled, making it easy to sew with a recessed part. Even if you tighten the thread firmly, there is no worry of the thread breaking, and it adheres closely to the fabric. For attaching buttons to doll clothes Dolls Licca-chan Blythe Oshi-katsu (Supporting your favorite idol/character)