Featured is a Willie Mays & Monte Irvin dual signed baseball. This baseball was hand signed by Willie Mays & Monte Irvin and has been authenticated by Beckett authentication services. Included with the baseball is Beckett hologram and letter of authenticity. This item would make a great addition to any sports memorabilia collection!.. SPECIFICATIONS Autographed By: Willie Mays Team: San Francisco Giants Sport: Baseball Authentication: Beckett Grading Services