Boru Men&rsquo;s Irish Tie Tack Celtic Cross Design Sterling Silver Made in Ireland Irish tie tack measures approximately  in diameter. Crafted from sterling silver for a nickel and allergy free tie tack. Tie tack is outfitted with a chain, a design that will keep the tie securely in place. Made by Boru Jewelry in Co. Dublin, Ireland. Hallmark stamped at Dublin Castle.