Bo knows baseball. Bo Jackson was a tremendous all-around athlete who won the 1985 Heisman Trophy as a running back for Auburn, then played successfully for the NFL's Oakland Raiders, becoming an All-Star. During his four seasons of professional football, Jackson also played successfully in the outfield for the Kansas City Royals, averaging 27 homers per year and making the American League All-Star team. He is the only athlete to ever have made All-Star teams in both pro football Major League baseball. After a football hip injury in 1990, Bo played only baseball. This helmet was worn in games by Jackson during his time with the White Sox in the early 1990s. Black helmet shows really nice use with "Sox" logo on the front and Chicago City flag on the back along with "8" sticker. Inside is American Baseball Cap sticker for size 7 1/8. Date of manufacture "clock" inside indicates March of 1990 which makes perfect sense that the shell was molded in 1990 and used in 1991 or later. Signed in 8/10 silver Sharpie on the brim and comes with JSA letter for the signature. Also comes with MEARS letter and letter from the original owner who worked for the White Sox. Heavy use shown.