I HAVE HUNDREDS OF TIE TACKS, TIE BARS AND CUFF LINKS. tie tack/bar: 0.77" x 0.56" (3/4" x 9/16" or 19.5mm x 14mm). collar bar: none. 0.25" = 1/4" or 6mm - pretty small for standard button holes. 0.38" = 3/8" or 9mm - also fits standard button holes.
This product would be perfect for vintage clothing enthusiasts or monogram lovers searching for a small, unique, and stylish letter initial.
