Red Wing X Brooks Brothers 6 Beckman Bison Leather Boots 4557 Mens Nitrile Cork. Size: US Men's 10 (Rare) This is a very rare model of limited edition Red Wing boots from a collaboration with Brooks Brothers. The #4557 in Black Bison Leather, all leather in sole, classic cork nitrile sole. A real grail pair for Red Wing collectors! BEAUTIFUL CONDITION