I HAVE HUNDREDS OF TIE TACKS, TIE BARS AND CUFF LINKS. tie tack/bar: 2.01" x 0.58" (2" x 9/16" or 51mm x 14.5mm). collar bar: none. I always try to point out any clear blemishes and condition. 0.25" = 1/4" or 6mm - pretty small for standard button holes.