Mizuno 3/4 Sleeve Premier Stretch Baselayer - Men's Mizuno's Stretch Baselayer is a 3/4-sleeve style, made from lightweight MzO™ micro-fiber polyester with Lycra® for greater movement. The design, including the low crew neck, is created especially for baseball movements. The Dynamic Friction Cut is Mizuno's combination of performance fabrics and sport-specific patterns. This eliminates any stress in the fabric and avoids limiting your range of motion. Imported.