I HAVE HUNDREDS OF TIE TACKS, TIE BARS AND CUFF LINKS. tie tack/bar: 1.89" x 0.78" (1-7/8" x 3/4" or 47.5mm x 19.5mm). 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.