Youth Baseball/Softball Heart Shield Protector (Worn Under Little Leaguers Uniform Jersey) Baseball & Softball Pitcher/Fielder & Batter's Heart Shield Protector. Low Profile Design to be worn under the Uniform Jersey. Easy On/Off Velcro Elastic Straps. 2 Sizes in Youth Medium (Typically Ages 9 & Under) and Youth Large (Ages 9 & Older). Worn by youth players in Little League, Pony, Travel Ball, ASA, etc.