Easton Men's M10 3/4 Sleeve Compression Shirt 88% Polyester, 12% Spandex Imported M10 3/4 is the perfect base layer for the M10 homeplate jersey Under arm and back have 4 way stretch mesh insert for ventilation and mobility Ergonomic 3D pattern for enhanced range of motion Contrast topstitch and ht logos Abrasion resistant cover stitched seams throughout