Boston Red Sox Kids alternate clean up hat. This is the kids version of the style the players wear on special occasions. Kids navy Red Sox cotton garment washed hat with embroidered pair of sox on the front and adjustable strap in the back. Generally we say Inf - Newborn to 2 years, Tod - 2 years to 4 years, Kids - 4 years to 6 years, Youth - 6 years to 8 years, 8 years and up should move to adult sized hats.